UNIVERSITY  OF  CALIFORNIA   PUBLICATIONS 

COLLEGE  OF  AGRICULTURE 

AGRICULTURAL  EXPERIMENT  STATION 

BERKELEY,  CALIFORNIA 


FRUIT  BEVERAGE  INVESTIGATIONS 


BY 

W.  V.  CRUESS  and  J.  H.  IRISH 


BULLETIN  No.  359 

April,  1923 


UNIVERSITY  OF  CALIFORNIA  PRESS 

BERKELEY,  CALIFORNIA 

1923 


David  P.  Barrows,  President  of  the  University. 


EXPERIMENT  STATION  STAFF 

HEADS  OF  DIVISIONS 

Thomas  Forsyth  Hunt,  Dean. 

Edward  J.  Wickson,  Horticulture  (Emeritus). 

,  Director  of  Resident  Instruction. 

C.  M.  Haring,  Veterinary  Science,  Director  of  Agricultural  Experiment  Station. 

B.  H.  Crocheron,  Director  of  Agricultural  Extension. 

C.  B.  Hutchison,  Plant  Breeding,  Director  of  the  Branch  of  the  College  of 

Agriculture  at  Davis. 
H.  J.  Webber,  Sub-tropical  Horticulture,  Director  of  Citrus  Experiment  Station. 
William  A.  Setchell,  Botany. 
Myer  E.  Jaffa,  Nutrition. 
Ralph  E.  Smith,  Plant  Pathology. 
John  W.  Gilmore,  Agronomy. 
Charles  F.  Shaw,  Soil  Technology. 
John  W.  Gregg,  Landscape  Gardening  and  Floriculture. 
Frederic  T.  Bioletti,  Viticulture  and  Fruit  Products. 
Warren  T.  Clarke,  Agricultural  Extension. 
Ernest  B.  Babcock,  Genetics. 
Gordon  H.  True,  Animal  Husbandry. 
Walter  Mulford,  Forestry. 
James  T.  Barrett,  Plant  Pathology. 
W.  P.  Kelley,  Agricultural  Chemistry. 
H.  J.  Quayle,  Entomology. 
Elwood  Mead,  Rural  Institutions. 
H.  S.  Reed,  Plant  Physiology. 
L.  D.  Batchelor,  Orchard  Management. 
W.  L.  Howard,  Pomology. 
'Frank  Adams,  Irrigation  Investigations. 

C.  L.  Roadhouse,  Dairy  Industry. 
R.  L.  Adams,  Farm  Management. 

W.  B.  Herms,  Entomology  and  Parasitology. 
John  E.  Dougherty,  Poultry  Husbandry. 

D.  R.  Hoagland,  Plant  Nutrition. 
G.  H.  Hart,  Veterinary  Science. 

L.  J.  Fletcher,  Agricultural  Engineering. 
Edwin  C.  Voorhies,  Assistant  to  the  Dean. 

DIVISION  OF  VITICULTURE  AND  FRUIT  PRODUCTS 

F.  T.  Bioletti  L.  O.  Bonnet 

W.  V.  Cruess  A.  J.  Winkler 

A.  W.  Christie  H.  E.  Jacob 

J.  II.  Irish 


*  In  cooperation  with  Division  of  Agricultural  Engineering,  Bureau  of  Public  Roads,  U.  S. 
Department  of  Agriculture. 


FRUIT  BEVERAGE  INVESTIGATIONS 


BY 
W.  V.  CRUESS  and  J.  H.  IRISH 


CONTENTS  page 

Extent  of  the  beverage  industry 526 

Types  of  unfermented  bottled  beverages 526 

Preparation  of  syrups  for  bottling 527 

Raw  materials 527 

Maturity  of  the  fruit 529 

Harvesting  and  transportation  of  fruit 530 

Sorting  and  washing 530 

Crushing 531 

Heating 532 

Pressing : 534 

Clearing  the  juice 534 

Syrups  by  addition  of  sugar 538 

Concentration  in  vacuo 539 

Concentration  by  freezing 544 

Condensation  of  volatile  flavoring  compounds 544 

Concentration  by  the  spray  process 546 

Syrups  from  dried  fruits 546 

Blending  of  syrups 548 

Preservation  of  fruit  syrups 549 

Cold  storage 549 

Pasteurization 550 

Chemical  preservatives 550 

Uses  for  Fruit  Syrups 551 

In  soda  fountains 551 

For  carbonated  bottle  beverages 551 

In  the  home 551 

In  frozen  desserts 552 

In  confections 552 

In  jellies 553 

Use  of  fruit  syrups  in  carbonated  beverages 553 

Carbonating  and  bottling  equipment  at  the  university 553 

Carbonating  and  crowning 554 

Comparison  of  waters  used  in  carbonated  beverages 556 

Pasteurization  experiments 557 

Heat  penetration 558 

Commercial  pasteurization  of  bottled  carbonated  beverages 559 

[  Keeping  quality  of  fruit  beverages 561 

Use  of  fruit  syrups  by  commercial  bottlers 562 

Semi  commercial  production  and  sale 562 

Syrups 562 

Bottled  beverages 563 

Carbonated  beverages  in  bulk 564 

Cost  of  production  of  fruit  syrups  and  carbonated  beverages 564 

Summary  and  conclusions 567 


526  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

In  1921  the  California  State  Legislature  appropriated  a  special 
fund  for  the  study  of  new  and  improved  methods  of  utilizing  Cali- 
fornia fruits.  The  investigations  reported  in  this  publication  form  an 
important  part  of  the  studies  made  possible  by  this  appropriation. 

Extent  of  the  Beverage  Industry. — According  to  the  annual  report 
of  the  Commissioner  of  Internal  Revenue,  the  value  of  all  soft  drinks, 
exclusive  of  mineral  waters,  consumed  in  the  United  States  and  posses- 
sions for  the  year  ending  June  30,  1921,  was  $618,394,565.90.  The 
value  of  bottled  beverages,  other  than  unf ermented  grape  juice,  ginger 
ale  and  mineral  waters,  was  $242,962,794.70.  At  an  average  of  five 
cents  per  bottle,  this  would  represent  nearly  5,000,000,000  bottles,  or 
approximately  forty-five  bottles  per  capita.  Unfermented  cider  is 
not  listed  in  the  report.  This  represents  an  increase  of  approximately 
66  per  cent  over  the  consumption  estimated  by  the  United  States 
Department  of  Agriculture  for  1918.* 

Of  the  totals  given  above,  California  produces  approximately  3.4 
per  cent  of  the  unfermented  grape  juice  and  natural  mineral  waters, 
2.5  per  cent  of  the  cereal  beverages,  and  5.1  per  cent  of  the  remaining 
soft  drinks. 

The  commissioner's  report  shows  that,  of  the  beverages  consumed 
in  America,  only  a  very  small  proportion  is  made  from  fruits.  Our 
investigations  have  demonstrated  that  it  is  possible  to  prepare  from 
fruits,  at  a  moderate  cost,  beverages  superior  in  quality  to  the  imita- 
tion fruit  beverages  now  sold  in  such  large  quantities.  California  is 
in  a  particularly  favorable  position  to  produce  such  fruit  beverages. 

Types  of  Unfermented  Bottled  Beverages. — The  principal  classes 
of  bottled  beverages  are  (1)  cereal  beverages,  prepared  usually  from 
barley  malt  and  hops;  (2)  imitation  fruit  beverages,  which  are  often 
given  fanciful  names  such  as  "crush,"  "squeeze,"  "squash,"  pre- 
ceded by  the  name  of  a  fruit;  (3)  mineral  waters,  natural  and  artifi- 
cial, and  (4)  fruit  beverages,  still  and  carbonated. 

There  are  two  kinds  of  imitation  fruit  beverages.  The  cheaper  type 
is  prepared  entirely  from  sugar,  water,  and  citric  or  tartaric  acid 
with  artificial  color  and  flavor.  No  fruit  juice  is  used.  The  other 
kind  is  prepared  in  a  similar  way  but  with  the  addition  of  a  small 
amount  of  fruit  juice  or  syrup,  or  of  fruit  distillate.  Most  of  the 
so-called  "true  fruit"  syrups  and  flavors  are  of  this  second  type.  The 
name  ' '  true  fruit ' '  is  misleading,  because  much  of  the  flavor  and  color 
of  the  product  is  derived  from  coal  tar  products  and  sources  other  than 
fruits. 


*  Weekly  News  Letter  U.  S.  D.  A.,  May  14,  1919,  estimates  consumption  at 
3,000,000,000  bottles  per  year. 


BULLETIN   359]  FRUIT  BEVERAGE  INVESTIGATIONS  527 

Most  of  the  so-called  "strawberry,"  "raspberry,"  "lemon,"  and 
other  bottled  soda  waters  contain  no  fruit  juice  or  other  fruit  product. 
In  many  cases  these  imitations  are  not  labeled  prominently  as  imi- 
tations. 

Of  the  carbonated  fruit  beverages  on  the  market,  carbonated  apple 
juice  is  the  most  important  and  most  popular.  Carbonated  logan- 
berry and  pineapple  beverages  prepared  from  the  juice  of  the  fruits, 
sugar,  and  carbonated  water  are  also  obtainable,  but  are  produced 
on  a  less  extensive  scale.  Attempts  to  produce  bottled  carbonated 
citrus  fruit  beverages  have  not  been  successful  commercially,  because 
of  the  tendency  for  these  products  to  deteriorate  rapidly  in  flavor 
and  color  after  bottling.  Most  of  the  so-called  citrus  beverages  sold 
in  bottles  are  prepared  wholly  or  in  part  with  artificial  color,  flavor, 
and  other  ingredients  which  are  not  fruit  juices. 

The  most  important  non-carbonated  bottled  fruit  juices  are  made 
from  grapes,  apples,  pineapples,  and  loganberries. 

PREPAEATION  OF  SYRUPS  FOE  BOTTLING 

Syrups  are  used  in  soda  fountains  and  by  soda  water  bottlers  in 
preference  to  fruit  juices  as  the  basis  for  carbonated  beverages.  An 
important  part  of  our  investigations,  therefore,  has  been  the  study 
of  methods  of  preparing  pure  fruit  syrups  for  this  purpose. 

Raiv  Materials. — There  are  available  in  California  for  the  prepara- 
tion of  fruit  juices  and  syrups  large  quantities  of  cull  apples,  oranges, 
lemons,  grape  fruit,  table  grapes,  berries,  and  pomegranates.  This 
cull  fruit,  although  generally  unsuitable  for  fresh  shipment,  canning, 
or  drying,  is  often  of  equal  value  with  the  better  grades  of  fruit  for 
the  making  of  syrups  and  juice. 

The  Yellow  Newtown,  Gravenstein,  and  Bell  Flower,  are  the  princi- 
pal varieties  of  apples  available  for  juice  in  central  California,  and 
the  Rome  Beauty,  Winesap,  and  Deliciov.s,  in  southern  California. 
All  these  varieties  are  satisfactory  for  cider,  although  the  Yellow  New- 
town, Winesap,  and  Rome  Beauty  are  best  for  this  purpose  on  account 
of  their  more  pronounced  flavor  and  higher  acidity. 

There  is  estimated  to  be  available  in  this  state  enough  cull  apples 
suitable  for  juice  to  yield  at  least  one  million  gallons  of  cider  a  year. 

In  normal  years  probably  not  less  than  five  per  cent  of  the  orange 
crop  is  discarded  in  the  orchards  and  packing  houses  as  culls.  In 
years  of  heavy  frost  damage  the  percentage  of  cull  fruit  is  much 
higher.  Cull  unfrosted  oranges  are  equal  to  the  packed  fruit  for 
juice  purposes.    Frosted  oranges  are  also  satisfactory  if  utilized  before 


528  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

the  fruit  has  undergone  severe  drying  and  change  in  flavor  after 
freezing.  There  are  probably  enough  cull  oranges  available  to  yield 
two  million  to  five  million  gallons  of  juice  a  year. 

Lemons  unsuitable  for  fresh  shipment  are  now  utilized  to  a  large 
extent  for  the  manufacture  of  citric  acid  and  lemon  oil.  Most  of  this 
fruit  is  also  satisfactory  for  the  preparation  of  lemon  juice  and  syrup. 

Pomelos  (grape  fruit)  are  not  grown  very  extensively  in  California 
and  the  amount  available  for  by-products  is  small  in  comparison 
with  that  of  oranges  and  lemons. 

Second  crop  Muscat  grapes  usually  ripen  so  late  that  they  cannot 
be  made  into  raisins  by  sun  drying,  and  are  often  not  harvested.  They 
are  excellent  for  the  making  of  juice  and  syrup. 

The  tonnage  of  second  crop  Muscat  grapes  varies  greatly  from 
year  to  year,  but  an  average  of  at  least  twenty  thousand  tons  is  avail- 
able yearly.  This  amount  would  yield  about  three  million  gallons  of 
juice. 

Cull  table  grapes  yield  juices  lacking  in  distinctive  flavor,  but  their 
juices  can  be  used  if  blended  with  more  highly  flavored  juices. 

Muscat  raisins  of  the  smaller  sizes  are  difficult  to  market.  The  seeds 
and  waste  wash-water  from  the  seeding  of  Muscat  raisins  contain 
about  twenty  per  cent  of  sugar.  All  of  these  materials  have  been 
found  to  yield  syrups  suitable  for  use  as  a  base  for  carbonated 
beverages. 

The  production  of  wine  grapes  of  all  varieties  in  California  is 
approximately  five  hundred  thousand  tons  a  year.  Much  of  this  is 
available  for  the  preparation  of  syrups  and  unfermented  beverages. 

Strawberries  and  other  berries,  too  small  or  too  ripe  for  fresh 
shipment  or  for  preserving,  may  be  utilized  with  advantage  as  raw 
materials  for  preparing  soda  fountain  and  bottling  syrups.  Straw- 
berries, loganberries,  and  blackberries  (Lawton,  Himalaya,  and  Mam- 
moth varieties)  are  available  in  sufficient  quantities  for  the  commercial 
production  of  syrups.  Raspberries  are  not  produced  in  sufficient  vol- 
ume and  are  too  high  priced  in  California  for  this  purpose. 

Pomegranates  are  being  planted  extensively  in  the  San  Joaquin 
Valley.  A  large  proportion  of  the  fruit  splits  on  the  tree  and  is  on 
this  account  unsuitable  for  fresh  shipment.  The  split  fruit,  is,  how- 
ever, equal  to  the  whole  fruit  for  juice  making.  The  juice  is  of  deep 
red  color  and  pleasing  flavor  and  blends  well  with  other  juices. 

Pineapple  beverages  are  popular.  Pineapple  juice  and  syrup  are 
now  produced  on  a  commercial  scale  in  the  Hawaiian  Islands  and 
are  available  at  moderate  prices  for  the  use  of  bottlers  and  soda- 
fountains. 


Bulletin  359] 


FRUIT  BEVERAGE  INVESTIGATIONS 


529 


Maturity  of  the  Fruit. — In  our  experiments  the  effect  of  the  ma- 
turity of  the  fruit  on  the  quality  of  the  product  was  studied.  As  a 
result  of  these  investigations  the  following  recommendations  are  made. 

Apples  for  juice  should  be  crisp  and  firm  and  not  mealy.  When 
thoroughly  ripe  they  often  yield  juice  deficient  in  flavor  and  acidity, 
and  difficult  to  filter. 


Fig.  1. — Balling  hydrometer,  hydrometer  cylinder,  and  thermometer. 

Oranges  should  be  fully  matured  because  when  unripe  they  pro- 
duce a  bitter  juice.  Often  oranges  ripe  enough  to  conform  to  the  8  :1 
Balling-acid  test  yield  a  juice  which  rapidly  becomes  bitter  after 
expression. 

Red  wine  grapes  for  juice  should  be  harvested  when  they  test 
18-21°  Balling. 

First  crop  Muscat  grapes  are  best  at  approximately  22°  Balling. 
Grapes  grown  in  California  tend  to  become  too  sweet  and  too  low  in 
acidity  for  use  as  juice.     If  they  are  to  be  used  in  the  preparation 


530  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

of  syrup  they  should  be  allowed  to  attain  22-24°  Balling.  The  syrup 
is  used  in  preparing  carbonated  beverages  and  any  slight  deficiency 
in  natural  acidity  is  made  up  by  the  '  sharpness '  of  the  carbon  dioxide. 
Second  crop  Muscat  grapes  are  more  tart  and  lower  in  sugar  content 
than  first  crop  grapes.  They  should  be  allowed  to  become  as  rich  in 
sugar  before  harvesting  as  the  season  will  permit. 

Berries  should  be  'soft  ripe'  when  used  for  juice  or  syrup,  in 
order  to  obtain  the  maximum  flavor,  color,  and  sweetness.  This  is 
particularly  true  of  loganberries. 

We  have  found  that  pomegranates  also  should  be  fully  matured  in 
order  that  the  juice  will  be  of  deep  red  color  and  of  the  best  flavor. 

Harvesting  and  Transportation  of  the  Fruit. — Too  little  care  often 
is  taken  in  the  harvesting  and  transportation  of  fruit  to  be  used  for 
juice  or  syrup.  Firm  fruits  may  be  harvested  in  lug  boxes.  Berries 
must  be  placed  in  shallow  drawers  or  boxes  in  order  to  avoid  crushing 
and  consequent  loss  of  juice. 

Fruit  boxes  and  berry  drawers  must  be  clean  and  as  free  as  possi- 
ble from  decayed  fruit,  mold,  and  soured  juice.  The  boxes  should  be 
washed  and  scrubbed  frequently,  particularly  if  the  fruit  tends  to 
break  down  during  shipment. 

Soft  fruits  such  as  berries  and  many  grapes  should  be  transported 
to  the  factory  and  converted  into  juice  or  syrup  with  as  little  delay 
as  possible.  Twenty-four  hours  should  be  the  maximum  time  between 
harvesting  and  crushing  of  soft  fruits. 

Firm  fruits  such  as  apples  and  citrus  fruits,  if  sound  and  harvested 
carefully,  may  often  be  held  in  storage  for  a  considerable  period 
before  crushing.  Cold  storage  apples  and  oranges  are  very  generally 
used  in  large  cities  in  cider  stands  where  fresh  cider  and  orange  juice 
are  sold. 

Sorting  and  Washing. — In  our  investigations  we  have  found  it 
necessary  to  sort  carefully  practically  all  varieties  of  fruits  before 
crushing.  Cull  oranges,  lemons,  and  apples  require  vigorous  washing 
to  remove  sooty  deposits,  dust,  etc.  The  brush  and  spray  washers 
used  in  washing  citrus  fruits  for  fresh  shipment  would  be  suitable 
for  washing  apples,  citrus  fruits,  and  pomegranates  to  be  used  for 
juices. 

Grapes  can  be  washed  satisfactorily  by  vigorous  sprays  of  water. 
Usually,  sorting  is  not  necessary  if  the  grapes  are  crushed  within 
twenty-four  hours  after  picking. 

Berries  must  be  very  carefully  sorted.  Gentle  sprays  of  water 
should  be  used  to  remove  dust. 


Bulletin  359] 


FRUIT   BEVERAGE   INVESTIGATIONS 


531 


Crushing. — It  was  found  that  citrus  fruits  could  be  pressed  most 
satisfactorily  if  merely  cut  in  halves  or  quarters ;  crushing  was  not 
necessary. 


Fig.  2. — Fruit  crusher  and  hydraulic  press  in  the  Fruit  Products  Laboratory. 

In  crushing  grapes  at  the  University  Farm  a  hand  power  crusher 
consisting  of  two  revolving  fluted  rolls  was  used.  At  Berkeley  the 
apple  grater  shown  in  figure  2  was  used.  White  grapes  were  crushed 
but  not  stemmed.  The  presence  of  the  stems  facilitated  pressing. 
Red  grapes  were  crushed  and  stemmed,  in  our  experiments  at  the 
University  Farm  at  Davis.  Since  these  grapes  were  heated  before 
pressing  it  was  found  desirable  to  remove  the  stems  before  heating,  in 
order  to  avoid  extraction  of  an  excessive  amount  of  tannin  and  'stem' 
flavor.  Heating  also  softened  the  crushed  berries  and  thereby  greatly 
facilitated  extraction  of  the  juice  by  pressing. 


532 


UNIVERSITY  OF  CALIFORNIA- — EXPERIMENT  STATION 


Apples  were  grated  before  pressing  by  means  of  a  power  driven 
apple  grater  of  a  standard  design  shown  in  figure  2.  This  grater  or 
crusher  consists  of  a  steel  cylinder  equipped  with  short  knives,  which 
revolves  toward  a  fluted,  curved  piece  of  cast  steel  which  is  parallel  to 
the  cylinder,  and  adjustable.  The  fruit  may  be  grated  to  any  degree 
of  fineness  by  adjustment  of  the  distance  between  the  revolving  cylin- 
der and  the  curved  plate. 


Fig.    3. — Steam    jacketed    kettles    and    pasteurizer    in    the    Fruit    Products 
Laboratory. 

Berries  were  crushed  in  a  tin  lined  Enterprise  combination  screw 
crusher  and  press.  (See  illustration  in  circular  220.)  Contact  with 
iron  injured  the  color  of  the  juice  and  for  this  reason  the  apple 
grater  was  not  used  for  berries. 

Crushed  pomegranates  yielded  a  very  astringent  juice  not  suitable 
for  beverage  purposes.  The  halved  fruit  was  difficult  to  press.  The 
best  results  were  obtained  by  pressing  the  whole  fruit  without  previous 
treatment  other  than  sorting  and  washing. 

II eat  lug. — Berries  and  red  grapes  were  heated  before  pressing  in 
order  to  extract  the  red  color  and  to  give  an  increased  yield  of  juice. 

In  the  experiments  at  the  University  Farm  the  crushed  red  grapes 
were  placed  in  the  basket  of  a-  large  hand  press  and  pressed  lightly. 
The  pressed  grapes  were  then  transferred  to  a  small  wooden  vat.    The 


Bulletin  359] 


FRUIT  BEVERAGE   INVESTIGATIONS 


533 


juice  was  heated  to  160-170°  F.  by  passing  it  through  a  water  jacketed 
aluminum  coil.  The  heated  juice  was  then  mixed  with  the  crushed 
grapes  giving  a  final  temperature  of  about  130°  F.  The  mixture  was 
allowed  to  stand  about  eight  hours  before  pressing.  Temperatures 
above  140°  F.  caused  the  extraction  of  an  excess  of  tannin  and  of 
disagreeable  flavors  from  the  seeds. 


Fig.  4. — Basket  press,  hand  power  size. 

At  Berkeley  the  crushed  grapes  were  heated  to  160°  F.  in  a  steam 
jacketed,  silver-lined  copper  jelly  kettle  and  pressed  at  once.  The 
juice  obtained  was  somewhat  harsher  in  flavor  than  the  juice  pre- 
pared by  extraction  of  the  color  at  130°  F.  Nevertheless,  the  juice 
from  grapes  heated  to  160°  F.  was  of  very  satisfactory  flavor  and  of 
excellent  color.  Petite  Sirah,  Barbera,  and  Alicante  Bouschet  gave 
juices  of  deeper  color  and  better  flavor  than  that  obtained  from 
Zinfandel. 


534  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

Berries  were  heated  to  140°  F.  and  pressed  at  once.  When  heated 
too  long,  a  large  amount  of  pectin  was  extracted  from  loganberries 
and  blackberries.  The  presence  of  pectin  caused  jelling  of  some  of 
these  syrups. 

Aluminum  was  found  to  affect  the  color  and  flavor  of  the  juices 
less  than  copper  or  tin.  Glass  lined  equipment  (heavily  enameled 
steel)  was  found  to  affect  the  flavor  and  color  of  the  juices  less  than 
any  of  the  metals  used  in  our  experiments.  These  included  iron,  nickel, 
silver,  zinc  (galvanized  iron),  aluminum,  copper,  and  tin.  Zinc 
and  iron  dissolved  rapidly  in  the  heated  juice,  and  after  a  few 
minutes'  contact  the  juice  was  undrinkable. 

Pressing. — Two  types  of  presses  were  used  in  our  experiments. 
One  of  these,  the  basket  style  of  grape  press,  shown  in  figure  4,  was 
found  to  be  very  satisfactory  for  pressing  of  grapes,  halved  citrus 
fruits,  and  whole  pomegranates.  It  was  found  desirable  to  line  the 
inside  of  the  basket  with  burlap,  straw,  or  heavy  press  cloth  in  order 
to  reduce  the  amount  of  pulp  expressed  with  the  juice. 

Berries  and  apples  were  pressed  through  coarsely  woven  press 
cloths  placed  between  wooden  racks  or  gratings  in  a  rack  and  cloth 
press  operated  by  hydraulic  pressure.  (See  figure  2.)  Berries  were 
placed  in  a  piece  of  closely  woven  cloth,  such  as  canvas,  inside  of  the 
coarsely  woven  press  cloth.  This  prevented  the  berry  pulp  from 
squeezing  out  through  the  press  cloth  into  the  juice,  thus  facilitating 
Alteration  of  the  juice  as  well  as  the  removal  of  the  pomace  from  the 
press  cloth. 

The  basket  press  was  not  suitable  for  these  fruits  because  it  did 
not  exert  sufficient  pressure.  Higher  yields  of  juice,  and  clearer  juice, 
from  grapes,  citrus  fruits,  and  pomegranates  were  obtained  by  use  of 
the  rack  and  cloth  press  than  from  the  basket  press,  although  the 
labor  cost  of  operation  with  the  rack  and  cloth  press  was  greater  than 
with  the  basket  press. 

In  commercial  practice  continuous  screw  presses  have  been  used  in 
two  or  three  factories  for  pressing  unfermented  grapes,  but  have 
proved  unsatisfactory  because  the  fruit  is  ground  to  a  ' 'puree,"  and 
the  resulting  juice  contains  an  excessive  amount  of  pulp,  which 
renders  filtration  extremely  difficult. 

For  general  purposes  the  rack  and  cloth  (fig.  2)  press  was  found 
the  most  satisfactory. 

Clearing  the  Juice. — Citrus  fruit  juices  were  found  to  be  most 
pleasing  in  flavor  and  appearance  when  used  without  removal  of  the 
pulp  by  Alteration  or  other  means.  The  presence  of  unbroken  juice 
sjics  in  orange  juice  or  syrups  improved  its  appearance. 


Bulletin  359] 


FRUIT   BEVERAGE   INVESTIGATIONS 


535 


Other  fruit  syrups  and  beverages  were  most  attractive  when 
perfectly  clear.  Several  methods  of  clearing  the  juices  were  studied. 
These  included  nitration,  fining,  and  centrifugal  clarification. 


Fig.  5.— Small  industrial  size  pulp  filter  (Karl  Kieffer). 


Filtration  was  found  to  be  the  most  practical  method  for  most 
juices.  The  pulp  filter  shown  in  figure  5  was  used  for  filtration  of 
most  of  the  large  lots  of  juice  prepared  at  Berkeley.  This  filter  con- 
sists of  two  discs  of  cotton  fiber,  each  about  one  inch  thick  and 
separated  by  a  silvered  screen  disc.     The  two  pulp  discs  act  as  inde- 


536 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


pendent  filters.  The  discs  are  formed  by  pressing  washed  cotton  fiber 
tightly  into  forms  designed  for  the  purpose.  The  discs  are  enclosed 
in  a  silver  lined,  circular  chamber  closed  with  a  large  rubber  gasket 
and  silver  lined  plate.  The  juices  were,  in  most  cases,  roughly  filtered 
through  coarse  felt  before  filtration  through  pulp   (see  figure  6). 


Fig.  6. — Felt  jelly  bag  for  preliminary  Alteration. 


The  juice  was  placed  in  a  tin  lined  cylinder  and  forced  through 
the  pulp  under  air  pressure.  One  filtration  through  lightly  pressed 
and  one  through  tightly  pressed  pulp  rendered  most  juices  brilliantly 
clear  and  did  not  impair  their  flavor.  The  rate  of  filtration  of 
Muscat  juice  was  100  gallons  an  hour  and  of  cider  120  gallons. 

A  small  pulp  filter  designed  for  filtering  fruit  juices  on  the  home 
scale  was  also  successfully  used.  This  filter  is  very  simple  in  design 
and  operation.  Suction  is  obtained  by  a  small  water  jet  pump,  which 
may  be  attached  to  any  water  faucet.    The  rate  of  filtration  for  most 


Bulletin  359] 


FRUIT  BEVERAGE   INVESTIGATIONS 


537 


fruit  juices  was  found  to  be  about  10  gallons  an  hour.     The  filter  is 
shown  in  figure  7. 

At  the  University  Farm  an  asbestos  filter  was  used.  This  consisted 
of  a  silver  lined  cylinder  inside  of  which  was  placed  a  fine  mesh  silver 
screen  cylinder.  Short  fiber  asbestos  was  mixed  with  the  juice  and  the 
mixture  poured  into  the  filter,  where  it  formed  a  filtering  layer  of 


Fig.  7. — "Cellulo"  pulp  filter,  suitable  for  small  scale  filtration. 

asbestos  about  one-half  inch  thick  on  the  screen.  The  juice  was 
forced  through  the  filter  by  gravity  pressure  obtained  by  connecting 
the  filter  inlet  to  a  reservoir  of  the  juice  placed  about  ten  feet  above 
the  filter.  The  filtration  was  slow,  but  the  filtered  juice  was  clear. 
This  filter  was  not  so  satisfactory  as  the  pulp  filters  described  above 
and  shown  in  figures  5  and  7. 

A  small  plate  and  frame  filter  press  was  used  in  several  experi- 
ments made  on  a  small  scale.  This  filter  press  consisted  of  twenty 
pieces  of  canvas  or  filter  cloth  placed  between  enamel  coated  steel 


538  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

plates  of  the  type  shown  in  figure  8.  The  plates  and  cloths  were  about 
six  inches  square  and  the  total  filtering  surface  about  ten  square 
feet.  It  was  found  necessary  to  coat  the  surface  of  the  filter  cloths 
with  infusorial  earth,  or  to  mix  this  material  with  the  juice  in  order 
to  hasten  filtration  and  to  obtain  a  clear  filtrate.  The  infusorial  earth 
used  in  our  experiments  was  a  finely  pulverized,  'fluffy'  product  sold 
under  the  name  of  Filter-Cel.  In  our  first  experiments  the  unheated 
earth  was  used.  This  imparted  an  "earthy'  taste  to  the  filtrate. 
This  flavor,  however,  was  in  later  experiments,  removed  from  the 
earth  by  washing  with  cold  water.  Washing  was  accomplished  by 
mixing  the  earth  with  water,  passing  the  mixture  into  the  filter  to 
coat  the  cloths  and  forcing  water  through  the  filter  until  the  filtrate 
no  longer  tasted  of  the  earth.  A  special  grade  of  the  Filter-Cel,  baked 
at  the  factory  to  remove  the  earthy  taste,  was  found  satisfactory  for 
mixing  directly  with  the  juice.  About  one-half  of  one  per  cent  to 
one  per  cent  of  the  earth  by  weight  was  used. 

In  commercial  juice  factories  large  plate  and  frame  presses  have 
been  used  successfully.  The  metal  parts  of  the  filter  must  be  coated 
with  tin  or  other  material  to  prevent  contact  of  the  juice  with  iron. 

Clarifying  by  adding  fining  materials,  such  as  casein,  egg  albumin, 
Spanish  clay,  etc.,  was  not  successful,  except  with  red  grape  juice. 
Filtration  was  found  to  be  more  satisfactory. 

High  speed  centrifugal  clarifiers  were  tested.  They  are  similar 
to  cream  separators  in  design.  The  bowl  of  the  separator  operates  at 
fifteen  thousand  to  thirty  thousand  R.P.M.  It  was  found  possible  to 
remove  coarse  particles  of  pulp,  but  not  to  obtain  a  brilliantly  clear 
liquid.  Centrifugal  clarifiers  would  be  useful  for  partial  clearing 
before  filtration. 

It  was  found  desirable  to  heat  most  fruit  juices  to  about  150-165° 
F.  and  to  allow  them  to  cool  before  filtration.  This  treatment  caused 
coagulation  of  proteins,  which  otherwise  tended  to  precipitate  and 
cause  cloudiness  of  the  juice  or  syrup  during  final  pasteurization  in 
the  bottle. 

Berries  were  heated  to  140°  F.  before  pressing.  This  heating 
accomplished  the  same  results  as  heating  other  juices  after  pressing. 

Apple  juice  was  an  exception  to  the  above  rule.  It  was  filtered 
without  previous  heating  and  in  most  cases  did  not  become  cloudy 
when  pasteurized  after  filtration. 

Syrups  by  Addition  of  Sugar. — Syrups  were  prepared  from  vari- 
ous juices  by  three  methods ;  namely,  addition  of  sugar,  concentration 
in  vacuo,  and  concentration  by  freezing. 


Bulletin  359]  FRUIT  BEVERAGE  INVESTIGATIONS  539 

The  most  satisfactory  syrups  for  bottling  purposes  were  obtained 
when  cane  sugar  was  added  to  berry,  lemon,  grape  fruit,  and  pome- 
granate juices.  These  juices  also  required  the  addition  of  sugar  to 
counterbalance  their  high  acidity  before  they  were  satisfactory  for 
beverage  purposes.  The  sugar  also  tended  to  retain  the  fresh  fruit 
flavor  and  color.  The  unsweetened  juices  deteriorated  rapidly  in  both 
color  and  flavor  after  pasteurization. 

Berry  juices  were  sweetened  to  various  degrees  Balling,  but  50° 
Balling  was  found  best  for  all  except  loganberry.  Addition  of  more 
sugar  caused  the  juice  to  jell  and  when  less  was  used  the  flavor  and 
color  were  not  so  well  retained.  This  corresponds  to  slightly  less  than 
equal  sugar  by  weight.  Loganberry  juice  made  up  to  50°  Balling 
jellied  when  pasteurized.  The  degree  of  sweetness  for  loganberry 
juice  therefore,  should  not  exceed  45°  Balling.  The  sugar  was  added 
after  filtration,  because  the  addition  of  sugar  greatly  increased  the 
viscosity  of  the  juice  and  impeded  filtration. 

The  sugar  was  dissolved  by  stirring  in  the  cold  juice  or  by  sus- 
pending it  in  a  cheese  cloth  bag  at  the  surface.  The  syrup  thus  pre- 
pared was  strained  through  cheese  cloth  in  order  to  remove  any 
lint  present  in  the  sugar  or  on  the  bag. 

Pomegranate  juice  was  sweetened  by  the  addition  of  sugar  to  35° 
Balling.  At  higher  concentrations,  the  beverage  obtained  when  the 
proper  proportion  of  carbonated  water  was  added  was  weak,  both  in 
color  and  flavor. 

Citrus  fruit  syrups  prepared  by  the  addition  of  sugar  were  brought 
to  65°  Balling.  At  lower  concentrations  the  flavor  of  the  citrus  fruit 
syrups  deteriorated  rapidly  in  storage.  The  most  satisfactory  syrup 
was  made  by  blending  approximately  three  parts  of  orange  juice 
with  one  part  of  lemon  juice  and  bringing  to  65°  Balling  by  the 
addition  of  sugar. 

Concentration  in  Vacuo. — When  fruit  juice  is  concentrated  in  an 
open  kettle  a  syrup  of  brown  color  and  molasses-like  flavor  is  obtained. 
Such  syrup  is  totally  unsuited  for  use  in  the  preparation  of  carbon- 
ated beverages.  Darkening  of  the  color  and  development  of  the 
molasses  flavor  are  caused  by  the  high  temperature  of  the  boiling 
syrup  at  atmospheric  pressure. 

In  the  open  at  sea  level  water  boils  at  212°  F.  and  heavy  syrups 
at  220°  F.,  or  above.  If  water  or  fruit  juice  is  placed  under  reduced 
pressure,  i.e.,  in  a  vacuum,  the  boiling  point  is  lowered  in  proportion 
to  the  degree  of  vacuum. 


540 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


Barometric  pressure  of  the  atmosphere  is  usually  expressed  in 
inches  of  mercury,  representing  the  height  in  inches  to  which  a  mer- 
cury column  will  be  raised  by  pressure  of  the  atmosphere.  Vacuum 
is  expressed  in  the  same  terms  as  atmospheric  pressure.  Vacuum  may 
be  expressed  as  "inches  of  pressure,"  or  as  "inches  of  vacuum." 
Thus,  "2  inches  positive  pressure,"  is  approximately  the  same  as 
27.8  "inches  vacuum."  In  commercial  practice  "inches  vacuum"  is 
the  more  common  term. 

Under  a  perfect  vacuum,  approximately  29.9  inches  vacuum,  the 
boiling  point  of  water  is  below  the  freezing  point,  32°  F.  Water  boils 
at  32°  F.  at  29.82  inches  vacuum.  At  28  inches  the  boiling  point  is 
approximately  100°  F.  At  a  high  vacuum  each  inch  increase  causes 
a  greater  drop  in  temperature  than  at  a  low  vacuum.  Thus,  increas- 
ing the  vacuum  from  28  to  29  inches  decreases  the  boiling  point  of 
water  about  25°  F.,  whereas  increasing  the  vacuum  from  26  to  27 
inches  decreases  the  boiling  point  only  about  10°  F.  The  relation 
between  the  boiling  point  and  vacuum  in  inches  of  mercury  is  given 
in  table. 

TABLE    1 
Relation  Between  the  Boiling  Point  of  Water  and  Vacuum  in  Inches 


Vacuum,  in  Inches, 

Boiling  Point, 

Vacuum,  in  Inches, 

Boiling  Point, 

Mercury 

F° 

Mercury 

F° 

29.8191 

32 

27.4040 

110 

29.7516 

40 

27.0050 

115 

29.6365 

50 

27.5530 

120 

29.5631 

55 

26.0400 

125 

29.4770 

60 

25.4800 

130 

29.3760 

65 

24.8300 

135 

29.4590 

70 

24.1100 

140 

29.1250 

75 

22.4200 

150 

28.9680 

80 

20.3200 

160 

28.7880 

85 

17.7700 

170 

28.5800 

90 

14.6700 

180 

28.3410 

95 

10.9300 

190 

28.0700 

100 

6.4700 

200 

27.7590 

105 

1 . 1600 

210 

0.0000 

212 

The  equipment  used  commercially  for  the  concentration  of  liquids 
under  vacuum  consists  of  a  closed  vessel,  the  vacuum  pan,  connected 
to  a  vacuum  pump,  which  exhausts  the  air  from  the  apparatus. 
Between  the  vacuum  pan  and  the  vacuum  pump  is  a  condenser  which 


Bulletin  359] 


FRUIT   BEVERAGE   INVESTIGATIONS 


541 


condenses  the  vapors  from  the  vacuum  pan  to  liquid  form.  The 
vacuum  pan  usually  consists  of  a  cylindrical  steam  jacketed  vessel, 
equipped  inside  with  a  steam  heated  coil,  or  steam  jacketed  vertical 
tubes   ( callandria ) . 

Vacuum  pumps  are  of  two  types,  wet  and  dry.  The  wet  vacuum 
pump  is  of  the  cylinder,  force  pump  type  and  is  usually  operated 
by  steam.  It  exhausts  not  only  the  air  from  the  vacuum  pan,  but 
also  the  condensed  vapors.  The  wet  pump  rarely  gives  a  vacuum 
greater  than  27  inches.     The  dry  vacuum  pump  is  so  connected  that 


Fig.  8. — Small  filter  press  showing  filter  cloths  and  frames  in  position. 

it  handles  only  the  air  from  the  pan.  In  this  case  the  condensed 
water  vapors  are  taken  care  of  by  a  "barometric  leg,"  a  pipe  about 
35  feet  high  dipping  beneath  water  at  its  lower  end.  The  barometric 
leg  is  connected  at  the  top  to  the  condenser  and  connection  to  the 
vacuum  pump  is  made  beyond  the  condenser.  By  use  of  the  dry 
vacuum  pump  28  to  29  inches  of  vacuum  is  readily  obtained  in  com- 
mercial practice. 

Condensers  are  of  two  types,  spray  or  jet,  and  surface  condensers. 
In  the  spray  or  jet  condenser  the  vapors  come  in  contact  with  a  spray 
or  jet  of  water  in  an  enclosed  chamber.  In  the  surface  condenser  the 
vapors  are  condensed  in  water  jacketed  coils  or  other  water  jacketed 
device.  The  spray  system  is  the  more  generally  used  because  of  its 
simplicity  and  efficiency. 

In  our  experiments  two  vacuum  pans  were  used.  One  of  these 
was  a  small  steam  jacketed,  silver  lined  copper  pan  which  permitted 
the  concentration  of  about  five  gallons  of  juice  to  a  charge.    The  other 


542  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

pan  was  constructed  of  glass  lined  steel,  was  steam  jacketed,  and  had 
a  capacity  of  about  ten  gallons  of  juice  to  a  charge.     (See  fig.  9.) 

Both  pans  were  connected  to  water  cooled  coil  condensers  and  to 
a  dry  rotary  vacuum  pump  capable  of  producing  about  27  inches  of 
vacuum  in  the  pans. 

In  comparing  the  two  pans  with  respect  to  the  concentration  of 
various  juices,  it  was  found  that  the  glass  lined  pan  caused  much  less 
injury  to  the  color  and  flavor  of  the  concentrate  than  did  the  metal 
pan,  when  the  pans  were  operated  under  similar  conditions.  Grape 
syrups  and  apple  syrup  suitable  for  the  preparation  of  carbonated 
beverages  were  made  successfully  by  vacuum  concentration. 

Apple  syrup  concentrated  under  vacuum  was  supplied  us  by  a 
company  located  in  Washington  state.  The  syrup  was  found  fairly 
satisfactory  for  use  in  the  preparation  of  a  carbonated  beverage. 

Orange  syrup  has  been  prepared  upon  a  commercial  scale  by  the 
Exchange  Orange  Products  Company  at  San  Dimas,  California,  and 
the  syrup  has  proved  very  satisfactory  in  the  preparation  of  carbon- 
ated beverages.  A  glass  lined  vacuum  pan  and  a  very  high  vacuum 
were  used  in  concentrating  the  juice. 

The  juice  from  which  the  syrup  was  prepared  was  obtained  by 
pressing  the  whole  fruit.  The  orange  oil  expressed  with  the  juice 
was  separated  from  the  juice  before  concentrating,  but  was  returned 
to  the  syrup  before  the  beverage  was  bottled  in  order  to  intensify 
the  flavor. 

Orange  syrup  deteriorated  in  flavor  during  storage,  but  was  still 
suitable  for  bottling  purposes  six  months  after  concentration.  C.  P. 
Wilson,  in  charge  of  investigations  on  orange  syrup  at  the  San  Dimas 
factory,  found  that  a  vacuum  of  at  least  28  inches  was  necessary  for 
the  production  of  syrup  of  pleasing  flavor. 

Orange  syrup  suitable  for  bottlers'  and  for  fountain  use  has  also 
been  prepared  commercially  by  Gould  and  Drake  of  San  Francisco, 
by  concentration  of  the  juice  under  vacuum.  It  has  therefore  been 
shown  that  grape,  apple,  and  orange  syrups  for  bottlers'  use  may  be 
successfully  prepared  commercially  by  vacuum  concentration. 

Grape  syrups  made  by  concentration  under  vacuum  have  retained 
their  flavor  and  color  in  glass  containers  for  more  than  a  year.  For 
details  of  grape  syrup  manufacture  see  Bulletin  321  of  this  station. 
This  publication  is  out  of  print  but  may  be  consulted  in  public 
libraries. 


Bulletin  359] 


FRUIT   BEVERAGE   INVESTIGATIONS 


543 


Fig.  9. — Glass  lined  vacuum  pan  in  the  Fruit  Products  Laboratory. 


544  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

Condensation  of  Volatile  Flavoring  Compounds. — The  concen- 
tration of  any  fruit  juice  by  boiling  under  a  vacuum  results  in  con- 
siderable loss  of  flavor  and  aroma  through  volatilization  of  compounds 
responsible  for  the  characteristic  flavor  and  aroma  of  the  fresh  juices. 
It  is  possible  to  condense  a  portion  of  these  volatile  compounds  with 
part  of  the  water  vapors  and  return  this  distillate  to  the  concentrated 
juice,  thereby  intensifying  the  flavor  and  aroma  of  the  syrup.  M.  K. 
Serailian  of  San  Francisco  has  developed  this  method  and  applied 
it  successfully  on  a  small  commercial  scale.  The  writers  have  applied 
this  method  in  the  laboratory  by  use  of  the  vacuum  pan  shown  in 
figure  9.  The  distillate  was  collected  and  concentrated  by  redistilla- 
tion and  added  to  the  syrup  with  notable  intensification  of  flavor  and 
aroma. 

Concentration  by  Freezing. — Maple  sap  is  often  concentrated 
naturally  by  allowing  some  of  the  sap  to  freeze  partially  in  buckets  or 
tubs.  Almost  pure  water  separates  in  large  ice  crystals,  leaving 
the  unfrozen  sap  enriched  in  sugar.  Cider  is  often  partially  con- 
centrated by  the  same  method. 

Eudo  Monti,  an  Italian,  was  one  of  the  first  to  apply  this  principle 
industrially.  One  of  his  methods  consists  in  freezing  the  juice  to  a 
mixture  of  ice  crystals  and  syrup  and  then  separating  the  ice  and 
syrup  by  gravity  in  a  tall,  refrigerated,  jacketed  cylinder.  In  another 
method  a  metal  cylinder  filled  with  the  freezing  solution  revolves  in 
a  tank  of  juice.    Ice  forms  on  the  cylinder  and  is  removed  by  scraping. 

H.  C.  Gore*  of  the  United  States  Department  of  Agriculture,  in 
experiments  at  Hood  River  in  1914,  adapted  the  concentration  of 
apple  juice  by  freezing  to  operations  on  a  commercial  scale.  The 
juice  was  frozen  to  a  mushy  mixture  of  ice  crystals  and  syrup  in  ice 
cans.  The  frozen  juice  was  crushed  and  the  ice  and  syrup  were 
separated  by  centrifugal  action  in  a  perforated  basket  centrifuge 
of  the  type  used  in  sugar  factories.  The  syrup  thus  obtained  was 
again  frozen,  then  broken  up  in  an  ice  crusher  and  centrifuged  a 
second  time. 

In  applying  Gore's  process  in  the  Fruit  Products  Laboratory  at 
the  University  of  California,  the  juice  was  allowed  to  freeze  at  10  to 
15°  F.  for  24  to  36  hours  in  agate  ware  buckets.  It  was  then  centri- 
fuged and  allowed  to  freeze  a  second  time  at  0  to  5°  F.  It  was  centri- 
fuged a  second  time.  Two  additional  freezings  and  centrif ugings  were 
generally  found  necessary  to  concentrate  the  juice  to  50°  Balling.  The 
centrifuge  shown  in  figure  10  was  used. 

*  Gore,  H.  C,  Apple  Syrup  and  Concentrated  Cider.     U.  S.  D.  A.  Year  Book, 
Separate  No.  639,   1914. 


Bulletin  359] 


FRUIT  BEVERAGE  INVESTIGATIONS 


545 


Grape  and  apple  juices  gave  excellent  syrups  by  the  freezing 
process.  Orange  and  lemon  juices  yielded  very  satisfactory  syrups 
when  made  to  about  30°  Balling  by  the  addition  of  cane  sugar  before 
freezing.  Unsweetened  orange  and  lemon  juices  developed  a  disagree- 
able flavor  during  the  concentration  process.  Berry  juices  tended  to 
turn  brown  in  color  and  lose  much  of  their  flavor,  unless  sweetened 
before   concentration. 


Fig.  10.— Basket  centrifuge  for  separation  of  ice  and  syrup 

In  the  Hawaiian  Islands,  pineapple  syrup  is  made  on  a  commercial 
scale  by  the  freezing  process.  This  syrup  is  of  rich  pineapple  flavor 
and  is  excellent  for  bottlers'  use. 

Less  energy  is  required  for  removal  of  water  from  fruit  juice  by 
freezing  than  by  evaporation  by  application  of  heat.  Approximately  80 
calories  of  energy  (heat)  is  required  for  freezing  a  gram  of  water  and 
approximately  537  calories  of  heat  is  required  for  evaporation  of  a 
gram  of  water ;  that  is,  more  than  six  times  as  much  heat  is  required 
for  the  latter  as  for  the  former  process.  In  practise,  however,  losses 
in  energy  during  conversion  of  mechanical  energy  into  heat  energy 
by  use  of  the  ammonia  cooling  system  and  the  extra  cost  of  handling 


546  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

the  juice  in  the  freezing  process,  probably  more  than  counterbalance 
any  saving  in  fuel  by  the  freezing  process.  Fruit  syrups  made  by  the 
freezing  process  are  undeniably  superior  in  flavor  to  those  produced 
by  ordinary  methods  of  vacuum  concentration. 

Grape  syrups  of  excellent  color  and  flavor  were  made  in  our 
experiments  by  blending  Muscat  syrup  made  by  the  freezing  process, 
with  red  grape  syrup  prepared  by  vacuum  concentration. 

Concentration  by  the  Spray  Process. — The  Merrill-Soule  Company, 
well  known  producers  of  powdered  milk,  have  prepared  powdered 
fruit  juices  by  the  process  in  use  for  concentrating  milk  to  a  powder. 
Powdered  lemon  juice  (sweetened  before  drying)  and  powdered  orange 
juice  from  this  company  have  been  examined.  The  lemon  juice 
powder  made  an  excellent  lemonade  when  dissolved  in  water.  The 
orange  juice  powder  was  lacking  in  flavor. 

An  attempt  was  made  in  1919  at  Ferndale,  in  cooperation  with 
C.  E.  Gray,  President  of  the  California  Central  Creameries,  to  con- 
centrate grape  juice  to  a  powder  in  a  large  milk  drying  apparatus. 
The  juice  was  sprayed  in  a  large  sheet  metal  chamber  into  a  blast  of 
heated  air.  Drying  was  almost  instantaneous.  It  was  found  that  the 
dehydrated  juice  melted  at  about  115°  F.  and  that  it  absorbed  water 
very  rapidly  from  the  air.  With  the  apparatus  used  in  the  experi- 
ment it  was  impossible  to  obtain  a  powder.  However,  a  small  quantity 
of  excellent  syrup  was  obtained. 

The  writers  believe  that  the  spray  drying  process  has  great  possi- 
bilities as  a  means  of  concentrating  fruit  juices,  but  realize  that 
further  experiments  are  necessary. 

Syrups  from  Dried  Fruits. — The  preservation  of  fruit  juices  and 
syrups  requires  more  space  than  equivalent  quantities  of  the  dried 
fruit.  Experiments  were  made  to  determine  the  suitability  of  dried 
fruits  for  the  preparation  of  syrups. 

Dehydrated  raspberries,  loganberries,  blackberries,  and  red  wine 
grapes  were  soaked  over  night  in  enough  water  to  return  to  the 
fruits  the  water  removed  in  drying.  The  fruits  were  then  pressed 
and  the  resulting  juices  made  to  50°  Balling  by  the  addition  of  sugar. 
None  of  the  syrups  was  satisfactory  for  the  preparation  of  carbonated 
beverages.  Further  experiments  using  improved  methods  of  dehy- 
dration are  contemplated. 

The  general  conclusion  from  the  use  of  dehydrated  fruits  was 
that,  although  syrups  of  fair  quality  can  be  made  from  such  material, 
the  syrups  are  notably  inferior  to  syrups  made  from  the  fresh  fruits. 


Bulletin  359]  fruit  beverage  investigations  547 

Seeded  Muscat  raisins  were  made  into  syrup  by  two  different 
methods.  In  one  method  two  gallons  of  water  was  placed  on  five 
pounds  of  raisins.*  The  mixture  was  heated  to  165°  F.  and  allowed 
to  stand  one  hour.  It  was  then  pressed  in  a  rack  and  cloth  cider 
press.  The  juice  thus  obtained  was  placed  on  a  second  five  pounds 
lot  of  raisins  and  treated  as  above.  This  procedure  was  repeated  on 
three  more  lots  of  raisins ;  a  total  of  five  lots  for  the  entire  experiment. 
Two  and  one-fourth  gallons  of  syrup  was  obtained.  The  Balling 
degrees  of  the  various  extracts  corrected  to  60°  F.  were : 

First  extraction  17°  Balling 

Second  extraction  29°  Balling 

Third  extraction  38°  Balling 

Fourth  extraction 45°  Balling 

Fifth  extraction 52°  Balling 

The  syrup  was  filtered  through  pulp  and  tested  for  use  in  carbon- 
ated beverages.  The  raisin  syrup  alone  gave  a  beverage  of  poor 
flavor,  but  when  blended  in  the  proportions  of  twelve  parts  of  raisin 
syrup,  two  parts  of  orange  syrup,  and  one  part  of  lemon  syrup,  a  syrup 
of  excellent  flavor  was  obtained. 

The  five  lots  of  extracted  raisins  from  the  above  experiment  were 
treated  in  succession  with  the  same  amount  of  water  as  in  the  first 
experiment  and  the  dilute  syrup  thus  obtained  was  used  to  extract  a 
sixth  lot  of  raisins  not  previously  extracted  with  water  or  syrup.  The 
Balling  degrees  of  the  different  extractions  corrected  to  60°  F.  were : 

First  extraction  10.0°  Balling 

Second  extraction 18.0°  Balling 

Third  extraction  21.5°  Balling 

Fourth  extraction 34.0°  Balling 

Fifth  extraction 42.0°  Balling 

Sixth  extraction  '. 4.9.0°  Balling 

The  quality  of  this  syrup  was  equal  to  that  of  the  syrup  from  the 
first  experiment. 

-  A  dilute  water  extract  of  the  raisins  was  concentrated  in  a  vacuum 
pan  to  60°  Balling.  The  syrup  was  reduced  to  50°  Balling  by  addi- 
tion of  the  dilute  raisin  extract.  The  syrup  had  less  Muscat  raisin 
flavor  than  the  syrup  that  was  obtained  by  the  repeated  extraction 
process.  It  made  a  very  pleasing  beverage,  however,  when  blended 
with  orange  and  lemon  syrups  and  diluted  with  carbonated  water. 

*  Experiment  performed  by  J.  G.  Brown. 


548  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION 

Bottlers  could  prepare  raisin  syrup  at  their  bottling  establishments 
from  the  seeded  Muscat  raisins,  or  a  central  factory  could  manufac- 
ture it  and  distribute  it,  pasteurized,  in  lacquered  cans,  or  glass  bottles 
to  bottlers. 

Syrup  prepared  from  figs  in  the  same  manner  as  that  from  raisins 
was  blended  with  orange  and  lemon  syrups  and  gave  a  satisfactory 
product  which  undoubtedly  could  be  used  successfully  in  beverages. 
It  has  a  laxative  property,  which  might  be  an  advantage. 

Blending  of  Syrups. — Our  tests  demonstrated  that  beverages  made 
from  certain  blends  of  two  or  more  fruit  syrups  were  very  popular. 
One  blend,  ' '  Fruit  Punch, ' '  was  particularly  well  received.  The  syrup 
was  first  made  by  blending  equal  volumes  of  loganberry,  orange,  and 
lemon  syrups  of  50°  Balling,  and  was  prepared  from  the  fresh  juices 
by  addition  of  sugar. 

Later  this  blend  of  syrup  was  made  by  blending  equal  volumes 
of  vacuum  concentrated  red  grape  syrup,  vacuum  concentrated  orange 
syrup  diluted  with  simple  syrup,  and  lemon  syrup  made  by  addition 
of  sugar  to  lemon  juice.  This  syrup  contained  a  larger  proportion  of 
fruit  juice  and  required  the  addition  of  less  sugar  than  the  syrup  in 
which  the  loganberries  were  used,  yet  it  was  quite  as  good. 

"Raisinade"  syrup,  a  blend  of  Muscat  raisin,  orange,  and  lemon 
syrups,  has  been  described  under  Syrups  from  Dried  Fruits ;  see 
page  547. 

Equal  volumes  of  pomegranate,  pomelo  (grape  fruit),  and  orange 
syrups  made  a  satisfactory  blend.  They  were  all  made  from  fresh 
juice  by  adding  sugar;  the  pomegranate  syrup  was  35°  Balling,  the 
others  65°. 

Strawberry  syrup  and  the  beverages  made  from  it  fade  and  become 
brown.  Blackberry  syrup  lacks  distinctive  flavor,  but  is  of  intense 
color.  When  one  volume  of  blackberry  syrup  is  blended  with  three 
volumes  of  strawberry  syrup,  a  syrup  of  rich  strawberry  flavor  and 
deep  red  color  is  obtained.  The  color  does  not  fade  rapidly,  either  in 
the  syrup  or  in  carbonated  beverages  made  from  it. 

Numerous  other  blends  of  syrups  such  as  red  grape  with  strawberry 
and  with  raspberry,  orange  with  pomegranate  and  apple,  and  apple 
with  raisin  were  prepared  and  made  into  carbonated  beverages.  Many 
of  these  blends  were  very  satisfactory. 

The  prospects  of  improving  the  quality  of  fountain  and  bottlers' 
syrups  and  of  increasing  the  range  of  products  through  the  blending 
of  various  fruit  syrups  are  indeed  promising. 


BULLETIN  359]  FRUIT  BEVERAGE  INVESTIGATIONS  549 


PRESERVATION  OF  FEUIT  SYRUPS 

Almost  all  of  the  fruit  syrups  prepared  in  our  experiments  were 
of  such  low  Balling  degree,  45-65°,  that  they  required  treatment  to 
prevent  their  spoiling. 

Preservation  by  pasteurization  in  bottles  and  in  cans,  by  the  use 
of  sodium  benzoate,  and  by  cold  storage  at  32°  F.  and  at  0-15°  F.  were 
compared. 

Cold  Storage. — Syrups  stored  at  32°  F.  without  pasteurization 
kept  well  during  the  first  two  months  of  storage,  except  a  few  samples 
which  developed  mold.  Nearly  all  samples  of  syrup  stored  at  32° 
F.  for  more  than  six  months  became  moldy  or  fermented.  Similar 
results  were  obtained  at  26°  F.  to  28°  F.  Syrups  pasteurized  in  sealed 
containers,  however,  did  not  spoil  and  retained  their  flavor  and  color 
much  more  satisfactorily  than  pasteurized  samples  held  at  room 
temperature. 

Storage  at  0  to  15°  F.  resulted  in  partial  freezing  of  the  syrups 
and  all  growth  of  mold  and  yeast  was  prevented.  It  was  found  neces- 
sary to  store  the  syrups  in  sealed  containers  in  order  to  prevent  absorp- 
tion of  a  'cold  storage'  flavor.  Five  gallon  carboys  and  inside  enam- 
eled cans  were  found  satisfactory.  The  syrups  increased  considerably 
in  volume  in  freezing  storage  and  it  was  necessary  to  leave  ample 
head  space  in  the  carboys  and  cans  to  prevent  breakage. 

Berries  packed  in  barrels  with  an  equal  weight  of  sugar  are  success- 
fully held  in  commercial  cold  storage  warehouses  at  18°  F.  Doubt- 
less this  temperature  would  also  prevent  spoiling  of  fruit  syrups. 

As  a  result  of  these  experiments  and  observations  it  is  recom- 
mended that  fruit  syrups  intended  to  be  held  in  cold  storage  be  placed 
in  inside  enameled  five  gallon  or  one  gallon  cans  and  that  the  cans 
be  sealed,  and  stored  at  not  above  18°  F.  The  canned  frozen  syrups 
may  be  delivered  to  bottlers  and  fountains  directly  from  the  cold 
storage  warehouse.  Such  syrups  should  be  used  within  four  or  five 
days,  unless  they  are  again  placed  in  cold  storage,  e.g.,  in  an  ice 
chest,  or  pasteurized  in  sealed  containers.  In  large  cities,  however, 
the  bottler  or  soda  fountain  could  obtain  the  frozen  syrups  as  needed 
and  in  such  quantities  that  they  could  be  used  before  spoiling.  Syrups 
packed  in  pint  or  quart  cans  might  be  delivered  to  grocers  or  other 
dealers  and  by  such  dealers  in  turn  to  individual  families  for  home 
use. 


550  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION 

The  present  rate  for  cold  storage  of  frozen  berries  packed  with 
sugar  is  Sl1^  cents  for  one  hundred  pounds  for  the  first  month  and 
I2V2  cents  a  month  thereafter.  This  would  correspond  to  about  4 
cents  and  l1/^  cents  per  gallon  respectively  for  freezing  storage  of 
syrups. 

The  idle  cold  storage  equipment  of  breweries  is  suitable  for  the 
bulk  storage  of  fruit  syrups. 

Where  freezing  storage  is  available  it  is  recommended  in  prefer- 
ence to  all  other  methods  of  preserving  fruit  syrups. 

Pasteurization. — Heating  in  sealed  containers  was  found  to  be  an 
effective  method  of  preservation. 

Non-carbonated  syrups  required  heating  to  175°  F.  for  thirty 
minutes  in  quart  bottles  and  for  forty-five  minutes  in  gallon  bottles. 

In  tin  containers,  heating  to  165°  F.  before  sealing  and  keeping  at 
this  temperature  for  thirty  minutes  after  sealing  was  sufficient. 

In  four  and  eight  ounce  jars  sealed  under  vacuum  only  150°  F. 
for  fifteen  minutes  was  necessary. 

Carbonated  juices  required  only  thirty  minutes'  heating  at  150°  F. 

The  causes  of  these  differences  are  (1)  that  the  removal  of  most 
of  the  oxygen  in  vacuum  sealing  and  in  sealing  cans  hot  prevents  the 
development  and  growth  of  molds  that  are  not  killed  at  the  lower 
temperatures  used.  (2)  The  presence  of  carbon  dioxide  in  the  carbon- 
ated liquids  has  the  same  effect. 

Syrups  retained  their  color  and  flavor  much  better  in  glass  than 
in  tin.  Red  syrups  in  plain  tin  faded  and  acquired  a  bluish  or 
purplish  tint.  In  lacquered  (inside  enameled)  cans  the  color  deterior- 
ated much  less  rapidly.  In  some  instances  the  lacquer  imparted  a 
disagreeable  flavor.  Loganberry  syrup,  after  pasteurization  at  175° 
F.  in  gallon  enamel  lined  cans  and  storage  for  six  months  at  room 
temperature  was  still  satisfactory  in  color  and  flavor  for  the  prepara- 
tion of  carbonated  beverages,  although  not  so  attractive  in  either 
respect  as  syrup  from  the  same  lot  stored  at  0  to  15°  F.  in  various 
containers. 

As  a  result  of  these  experiments  the  writers  recommend  the  use 
of  glass  containers  and  carbonated  or  vacuum  sealing  for  red  syrups. 
Cans  are  satisfactory  for  Muscat  grape  and  other  white  grape  syrup, 
though  glass  containers  are  more  attractive  and  permit  the  user  to 
inspect  the  syrup  before  purchase. 

Chemical  Preservatives. — Fruit  syrups  are  generally  preserved 
for  the  use  of  soda  fountains  and  bottlers  by  the  addition  of  one-tenth 
of  one  per  cent  of  sodium  benzoate. 


BULLETIN   359]  FRUIT  BEVERAGE  INVESTIGATIONS  551 

Examination  of  a  number  of  commercial  syrups  preserved  in  this 
manner  showed  that  the  preservative  imparted  a  disagreeable  *  burn- 
ing' flavor  to  the  syrup  and  in  many  cases  a  pronounced  'chemical' 
flavor  resembling  the  flavor  imparted  by  iodoform. 

While  the  use  of  sodium  benzoate  is  permitted  by  the  Pure  Food 
and  Drug  regulations  of  the  Federal  and  state  governments,  the  present 
tendency  among  food  manufacturers  in  general  is  to  substitute  pasteuri- 
zation or  sterilization.  Thus  tomato  catsup  is  no  longer  preserved  by 
benzoate  in  up-to-date  catsup  factories.  The  public  prefers  food  free 
from  chemical  preservatives. 

Sulfurous  acid  is  the  only  other  chemical  preservative  permitted 
by  law.  Its  use  for  preserving  fruit  syrups  for  bottlers '  and  fountain 
use  is  not  feasible  because  of  its  injury  to  the  flavor  of  the  products 
when  used  in  sufficient  quantity  to  prevent  spoiling.  The  use  of 
salicylic  acid  in  foods  is  prohibited  by  law. 

The  writers  recommend  preservation  by  pasteurization  or  cold 
storage  and  advise  against  the  use  of  chemical  preservatives  in  fruit 
syrups. 

USES  FOE   FRUIT   SYRUPS 

The  suitability  of  various  fruit  syrups  for  the  preparation  of 
carbonated  beverages,  soda  fountain  drinks,  frozen  desserts,  gelatin 
desserts,  confections,  jellies,  and  homemade  fruit  punch  was  studied. 

In  Soda  Fountains. — The  highly  flavored  syrups  were  found  excel- 
lent for  preparing  ice  cream  sodas,  carbonated  mixed  drinks,  and  as 
dressing  for  ice  cream.  One  objection  made  to  the  syrups  was  their 
liability  to  mold  or  ferment  after  several  days  standing  in  the  open 
bottle.  This  difficulty  may  be  overcome  by  adding  sugar  to  increase 
the  balling  to  about  65-70°  F.    Sodium  benzoate  should  not  be  used. 

In  Carbonated  Bottled  Beverages. — Most  of  the  syrups  produced 
in  our  experiments  were  found  suitable  for  the  preparation  of  carbon- 
ated bottled  drinks.  For  details  of  these  experiments  see  pages 
553  to  562. 

In  the  Home. — The  types  of  syrup  which  proved  most  satisfactory 
such  as  the  berry,  orange,  and  fruit  punch  syrups,  were  bottled  and 
pasteurized  in  eight  ounce  bottles.  These  were  used  in  various  ways 
by  many  housewives  of  Oakland  and  Berkeley. 

Fruit  punch  was  prepared  in  the  home  in  many  instances  by 
simply  diluting  the  syrups  with  water  and  crushed  ice,  or  with 
carbonated  syphon  water.  In  other  cases,  the  syrups  were  mixed 
with  fresh  lemon  or  orange  juice,  or  with  bottled  grape  juice,  water, 
and  sugar.  All  the  reports  received  upon  the  use  of  the  syrups  in 
this  manner  were  very  favorable. 


552  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

When  added  to  uncolored  and  unflavored  gelatin  and  water,  very 
pleasing  desserts  were  made.  The  gelatin,  first  dissolved  in  hot 
water,  was  mixed  with  enough  syrup  to  obtain  a  pleasing  flavor  and 
color.     The  berry  syrups  proved  most  popular  for  this  purpose. 

The  syrups  greatly  improved  the  flavor  of  fruit  cocktails  or  'start- 
ers' (i.e.,  sliced  fresh  or  canned  fruits,  such  as  mixtures  of  peaches, 
pears,  pineapple,  banana,  grape  fruit  etc.).  They  were  also  found 
suitable  for  use  in  the  preparation  of  pudding  sauces.  Other  similar 
uses  suggest  themselves.  The  past  year 's  experience  leads  the  writers 
to  believe  that  the  sale  of  fruit  syrups  for  household  use  affords  as 
important  an  outlet  as  the  bottling  industry  and  soda  fountain  trade. 

For  the  household  trade  the  small  containers,  e.g.,  eight  ounce 
bottles,  were  preferred,  although  there  was  some  demand  for  syrup 
in  larger  quantities  for  use  in  preparing  fruit  punch  to  serve  at 
dances  and  other  social  gatherings. 

In  Frozen  Desserts. — Ice  cream  and  water  ices  were  prepared  from 
the  syrups  experimentally  in  the  laboratory  by  S.  A.  Bjarnason,  a 
former  graduate  student,  and  by  others.  The  results  were  in  all 
cases  very  satisfactory.  Berry  syrups  and  Muscat  raisin  syrup  blended 
well  with  cream,  gelatin,  and  sugar  in  the  preparation  of  ice  cream. 

Although  these  experiments  were  not  extensive  they  were  suffi- 
ciently conclusive  to  warrant  recommendation  of  the  use  of  these 
syrups  in  ice  cream  and  water  ices  in  ice  cream  factories  and  in  the 
home. 

In  Confections. — The  syrups  were  made  into  centers  for  chocolate 
dipping  by  combining  them  with  pectin  and  sugar  and  concentrating  to 
a  boiling  point  of  225°  F.  Syrups  rich  in  pectin  (loganberry,  apple, 
and  lemon)  required  the  addition  of  less  pectin  than  others.  In 
general,  however,  the  addition  of  sufficient  pectin  or  pectin  syrup  to 
give  a  finished  product  containing  about  one  and  ont-half  per  cent 
pectin  was  found  desirable.  Satisfactory  results  were  obtained  by 
combining  one  and  one-half  ounces  of  dry  powdered  pectin,  two  pints 
of  berry  syrup,  two  pounds  of  sugar,  and  two  pints  of  water.  The 
pectin  and  sugar  were  first  dissolved  in  the  water,  then  mixed  with 
the  syrup  and  the  whole  concentrated  to  a  boiling  point  of  225°  F. 
The  hot  liquid  was  placed  to  a  depth  of  about  one  half -inch  in  oiled 
pans  to  cool  and  solidify.  It  was  then  cut  in  rectangular  pieces  and 
dipped  in  chocolate.  The  candy  was  produced  on  a  semi-commercial 
scale  and  was  well  received. 

Concentrated  berry  syrups  were  used  successfully  by  a  large 
candy  factory  for  flavoring  cream  fondant  used  as  centers  for  choco- 
late  cream  candies.     The   genuine   fresh   berry  syrups  were   found 


Bulletin  359]  FRUIT  BEVERAGE  INVESTIGATIONS  553 

markedly  superior  to  the  artificially  colored  and  flavored  imitation 
berry  syrups  used  for  this  purpose. 

In  Jellies. — The  syrups  were  used  successfully  for  the  preparation 
of  jellies.  In  most  cases  it  was  found  necessary  to  combine  them  with 
either  pectin  or  fruit  juices  rich  in  pectin.  Grape  syrups,  berry  syrups 
and  pomegranate  syrup  gave  excellent  jellies  when  prepared  in  the 
above  manner. 

While  suitable  for  the  home  preparation  of  jellies,  it  is  probable 
that  the  cost  would  be  too  great  for  commercial  jelly  manufacturers. 

USE  OF  FEUIT  SYRUPS  IN  CARBONATED  BEVERAGES 

Investigation  has  proved  that  a  very  small  percentage  of  the 
bottled  carbonated  beverages  now  on  the  market  contain  fruit  juice. 
A  very  large  quantity  of  imitation  orange  and  strawberry  drinks  is 
bottled  in  carbonated  form.  Recently  imitation  grape  syrup  has  been 
used  extensively  in  preparing  carbonated  bottled  drinks. 

The  principal  object  of  the  investigations  reported  in  this  bulletin 
has  been  to  determine  the  practicability  of  using  real  fruit  syrups 
in  carbonated  bottled  beverages. 

Carbonating  and  Bottling  Equipment  at  University. — A  small  high 
pressure  carbonating  machine  was  installed  in  the  fruit  products 
laboratory  in  November,  1921.  This  machine  consists  of  a  tin  lined 
heavy  walled  steel  cylindrical  tank  fitted  with  a  stirrer  and  small 
force  pump.  The  carbonating  chamber  holds  about  five  gallons  of 
water.  Water  can  be  forced  by  the  pump  into  the  cylinder  against 
pressure  of  carbon  dioxide  gas. 

Carbon  dioxide  gas  is  admitted  to  this  clyinder  from  a  cylinder 
of  the  liquefied  gas  through  a  regulating  valve  by  means  of  which 
any  desired  pressure  of  gas  can  be  maintained  in  the  carbonator.  At 
the  same  time  water  or  juice  is  pumped  and  sprayed  under  pressure 
into  the  carbonating  chamber  and  is  mixed  with  the  gas  by  the  stirring 
device.  The  pump  and  stirrer  are  operated  by  a  small  electric  motor 
which  is  controlled  by  an  automatic  switch.  The  switch  automatically 
cuts  off  the  current  to  the  motor  when  the  carbonating  chamber  has 
been  filled  with  liquid. 

This  small  crabonator  has  a  capacity  of  about  twenty  gallons  of 
water  or  juice  an  hour.    It  has  given  excellent  service. 

A  foot  power  crown  soda  bottling  and  capping  machine  was  used 
in  conjunction  with  the  carbonator.  This  machine  is  equipped  with 
an  adjustable  syrup  measuring  device,  by  means  of  which  the  desired 
volume  of  syrup  may  be  measured  into  each  bottle,  and  with  a  carbon- 
ated water  delivery  head,  by  means  of  which  the  bottles  may  be  filled 
with  carbonated  water  or  juice  directly  from  the  carbonating  chamber. 


554 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


It  was  found  possible  for  one  man  to  carbonate  and  crown  six 
hundred  bottles  of  beverage  in  eight  hours. 

Various  carbonating  and  bottling  machines  are  shown  in  figures 
11,  12,  and  13. 


Fig.  11. — Water  softening,  carbonating  and  bottling  equipment  in  the  Fruit 
Products  Laboratory. 

Carbonating  and  Crowning. — Seven  and  eight  ounce  soda  water 
bottles  were  used  in  our  bottling  experiments.  Most  of  the  syrups 
were  used  at  the  rate  of  one  and  one-half  fluid  ounces  (about 
forty-five  cubic  centimeters)  to  a  bottle,  the  bottling  machine  being 
adjusted  to  deliver  this  amount  of  syrup  to  each  bottle.  Carbonated 
water  was  added  to  fill  each  bottle  within  about  one  and  one-fourth 
inches  of  the  top  and  the  bottle  was  immediately  sealed  with  a  crown 
cap  applied  by  the  foot  power  crown  capper. 

Carbonated  beverages  were  made  from,  several  varieties  of  fruit 
syrups  with  water  charged  at  10,  20,  30,  40,  50,  and  60  pounds  pressure 
of  carbon  dioxide;  the  water  being  carbonated  at  about  50°  F.  Most 
of  the  persons  who  sampled  the  different  lots  preferred  those  carbon- 
ated at  30  or  40  pounds. 


Bulletin  359] 


FRUIT  BEVERAGE  INVESTIGATIONS 


555 


The  gas  pressure  indicated  by  the  gauge  on  the  carbonator  during 
the  carbonating  of  water  used  in  preparing  beverages  for  sale  was 
approximately  forty  pounds.  This  corresponds  to  a  pressure  of 
about  fifteen  pounds  to  the  square  inch  in  the  bottle  after  sealing. 
This  pressure  of  gas  was  preferred  by  most  consumers.  At  higher 
pressures  much  of  the  beverage  was  often  lost  by  frothing  when  the 
bottles  were  opened  and  the  juice  was  too  highly  charged  to  make 
a  pleasing  beverage.  At  much  lower  pressures  some  of  the  beverages 
were  rather  'flat'  in  taste  and  were  not  sufficiently  effervescent. 

The  water  in  our  experiments  was  used  at  a  temperature  of  about 
50°  F.  If  carbonated  at  temperatures  above  50°  F.,  it  was  necessary 
to  use  higher  pressures  in  order  to  attain  the  same  pressure  of  gas  in 
the  bottle  at  room  temperature  because  of  the  decrease  in  solubility  of 
the  gas  in  water  with  increase  in  temperature.  At  temperatures  lower 
than  50°  F.,  lower  gas  pressure  should  be  used  to  compensate  for  the 
increase  in  solubility  of  carbon  dioxide  with  decrease  in  temperature. 


Fig.  12. — Carbonated  water  storage  tank  and  continuous  bottle  pasteurizer. 
Henry  Brown  Company,  Glendale. 


556  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

Many  producers  of  carbonated  beverages  use  the  low  pressure 
system  of  carbonating.  The  syrup  and  water  are  mixed  in  a  large 
tank  at  a  temperature  at  or  near  the  freezing  point  of  water,  32°  F. 
At  this  low  temperature  the  solubility  of  the  carbon  dioxide  is  much 
greater  than  at  room  temperature.  Glass  lined  steel  tanks  are  gen- 
erally used  for  carbonating  liquids  at  low  pressure.  This  method 
greatly  simplifies  bottling  equipment  and  operations  and  gives  a 
product  of  more  uniform  character  and  gas  pressure.  Liquids  carbon- 
ated and  bottled  by  the  low  pressure  system  do  not  foam  so  excessively 
during  bottling  as  those  carbonated  at  high  pressure  at  room 
temperature. 

Small  bottling  works,  for  the  most  part,  still  use  the  high  pressure 
carbonating  system  and  automatic  filling  and  crowning  machines.  Bot- 
tles vary  greatly  in  size  and  owing  to  the  fact  that  the  same  volume 
of  syrup  is  measured  into  each  bottle,  regardless  of  its  size,  there  is 
considerable  variation  in  the  composition  of  the  beverage  in  different 
bottles.  High  pressure  carbonating  systems  do  not  require  refrigerat- 
ing facilities  and  in  general  are  less  costly  to  install  than  the  low 
pressure  system. 

Figures  11,  12,  and  13  show  typical  carbonating  and  bottling 
equipment. 

Comparison  of  Waters  Used  in  Carbonated  Beverages. — Bottlers 
use  several  types  of  water  in  carbonated  beverages.  The  more  pro- 
gressive use  distilled  water ;  some  use  filtered  water  and  others  plain 
tap  water.  Tap  water  varies  greatly  in  character  according  to  the 
locality  and  the  season. 

In  our  experiments,  distilled  water,  tap  water,  and  water  softened 
and  filtered  by  use  of  a  Borromite  water  softener  and  filter  were  com- 
pared. In  experiments  with  filtered  orange  syrup,  the  tap  water 
caused  a  flocculent  deposit  in  the  carbonated  beverage,  while  the 
samples  made  with  distilled  water,  and  with  water  from  the  Borro- 
mite filter  remained  clear.  With  other  syrups  the  difference  was 
similar,  but  not  so  pronounced,  although  more  deposit  formed  in  the 
bottles  containing  tap  water. 

In  the  water  softener  a  compound  of  sodium  is  used  which  precipi- 
tates calcium  and  magnesium  salts.  The  salts  of  these  metals  are 
the  principal  cause  of  hardness  of  water,  and  probably  one  of  the 
causes  of  cloudiness  and  precipitates  in  carbonated  beverages.  Sodium 
salts  dissolve  in  the  water  and  replace  the  precipitated  magnesium 
and  calcium  salts. 


Bulletin  359] 


FRUIT  BEVERAGE  INVESTIGATIONS 


557 


As  a  result  of  these  experiments  and  of  observations  in  bottling 
plants,  it  is  recommended  that  distilled  water  be  "used  in  preference  to 
tap  water  for  bottled  carbonated  beverages. 


Fig.  13. — Low  pressure  bottling  machine  and  bottle  sealer. 
Company,  Glendale. 


Henry  Brown 


Pasteurization  Experiments. — Carbonated  fruit  beverages  soon 
undergo  fermentation  unless  pasteurized.  Carbon  dioxide  prevents 
the  growth  of  mold,  a  fact  which  greatly  simplifies  pasteurization. 
Our  experiments  proved  that  a  temperature  of  150°  F.  destroyed  all 
yeast  cells  in  carbonated  juice.  In  non-carbonated  beverages  mold 
spores  frequently  develop  and  cause  spoiling  even  when  pasteurized 
at  175°. 


558  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

A  large  number  of  samples  of  bottled  cabonated  fruit  beverages 
were  inoculated  with  actively  fermenting  yeast  cultures,  spore  bearing 
bacteria,  and  the  spores  of  several  varieties  of  molds,  and  pasteurized 
at  various  temperatures  for  various  lengths  of  time.  The  numbers 
of  these  microorganisms  present  before  and  after  pasteurization  were 
determined  and  samples  were  incubated  at  about  80°  to  85°  F.  to 
hasten  spoiling  of  insufficiently  pasteurized  samples.  One  dozen 
bottles  were  used  for  each  test. 

The  following  observations  were  made.  Samples  inoculated  very 
heavily  with  active  yeast  did  not  ferment  after  being  pasteurized  at 
140°  F.  for  forty  minutes,  nor  at  150°  F.  for  thirty  minutes.  There 
was  no  appreciable  difference  in  the  flavor  of  beverages  pasteurized 
at  these  two  temperatures.  Some  mold  spores  survived  170°  F.  for 
thirty  minutes  but  were  unable  to  develop  in  the  carbonated  samples. 
In  non-carbonated  checks,  mold  developed  in  samples  heated  to  170° 
F.  or  lower  temperatures.  Heating  to  175°  F.  for  thirty  minutes  pre- 
vented mold  growth  in  non-carbonated  samples.  Spore  bearing  bacteria 
(Bacillus  snbtilis,  and  a  spore  bearing  bacillus  from  spoiled  canned 
vegetables)  survived  all  temperatures  used  in  our  experiments,  120° 
to  212°  F.,  but  did  not  increase  in  numbers  in  the  beverages  and  did 
not  cause  spoiling.  The  beverages  were  evidently  wholly  unsuited  to 
their  growth. 

From  these  experiments  it  was  decided  that  a  pasteurization  of 
150°  F.  for  thirty  minutes  or  of  140°  F.  for  forty  minutes  should  be 
recommended  for  carbonated  fruit  beverages.  A  pasteurization  of 
175°  F.  for  thirty  minutes  appears  to  be  necessary  for  non-carbonated 
fruit  juices  and  syrups  in  order  to  prevent  mold  growth. 

Heat  Penetration. — The  rate  of  heat  penetration  in  bottled  carbon- 
ated beverages  was  determined  several  times.  The  filled  bottles  were 
placed  in  a  rectangular  metal  tank  holding  about  one  hundred  and 
fifty  bottles.  The  bottles  were  placed  in  a  horizontal  position  and  the 
tank  was  filled  with  water  to  completely  cover  the  bottles.  Thermom- 
eters were  inserted  in  two  bottles  with  the  bulbs  near  the  center  of 
the  bottles.  The  water  was  heated  by  a  perforated  steam  pipe  to  the 
pasteurizing  temperature.  Temperature  readings  of  the  thermome- 
ters in  the  bottles  and  of  a  thermometer  immersed  in  the  water  of  the 
pasteurizing  tank  were  made  frequently. 

After  thirty  minutes  at  the  pasteurizing  temperature,  cold  water 
was  added  rapidly  to  displace  the  heated  water  and  readings  were 
taken  as  the  bottles  were  cooled  in  this  water.  Table  2  gives  the  results 
of  one  such  test. 


Bulletin  359] 


FRUIT  BEVERAGE  INVESTIGATIONS 


559 


In  this  test  the  pasteurizer  reached  the  pasteurizing  temperature 
in  seven  minutes.  The  centers  of  the  bottles  reached  144°  F.  in  twenty 
minutes  and  150°  F.  only  at  the  end  of  thirty-seven  minutes.  Figure 
14  shows  graphically  the  rates  of  heat  penetration. 


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Fig.  14. — Curves  showing  rates  of  heat  penetration  and  cooling  of  bottled 
beverages. 

Commercial  Pasteurization  of  Bottled  Beverages. — Most  carbon- 
ated beverages  now  on  the  market  are  not  pasteurized.  Pasteurization 
does  not  appear  to  be  necessary  for  synthetic  (artificial)  beverages. 
Cereal  beverages  and  those  in  which  some  fruit  juice  is  used  are 
pasteurized,  these  beverages  being  produced  in  most  cases  in  large, 
well  equipped  bottling  plants. 

Pasteurization  increases  the  cost  and  on  this  account  has  not  been 
adopted  generally  by  the  small  scale  bottlers.  It  is  possible,  however,  to 
build  relatively  inexpensive,  yet  efficient  pasteurizers  and  the  cost 
of  pasteurization  need  not  be  high. 

A  very  simple  pasteurizer  in  use  in  a  fruit  juice  factory  in  Contra 
Costa  County  consists  of  a  redwood  vat  about  ten  feet  long,  about 
three  feet  wide  and  about  two  and  one-half  feet  deep.     Several  turns 


560 


UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 


of  perforated  steam  pipe  in  the  bottom  of  the  tank  serve  for  heating 
the  water  used  in  pasteurizing.  A  wooden  grating  rests  on  the  coils 
and  prevents  direct  contact  of  the  bottles  with  the  steam  jets.  The 
bottles  are  stacked  in  the  pasteurizer  in  perforated  sheet  metal  crates 
and  are  covered  with  water.  Similar  pasteurizers  are  in  use  in  other 
juice  factories. 

TABLE  2 

Kates  of  Heat  Penetration  and  Cooling  of  Eight  Ounce  Bottles  of  Fruit 

Beverage 


Temperature  °F. 

Temperature  °F.  of  Bottle. 

Time  in  Minutes 

of  Pasteurizer 

Average  of  two  bottles 

0 

56 

58 

5 

134 

82 

7 

152 

102 

10 

152 

122 

15 

150 

137 

20 

150 

144 

25 

150 

147 

30 

150 

149 

35 

150 

149 

37 

150 

150 

Cooling  after  Pasteurizing 


0 

150 

150 

• 

3 

146 

148 

5 

136 

146 

8 

124 

140 

10 

122 

131 

13 

106 

124 

15 

98 

118 

18 

80 

102 

20 

76 

95 

23 

68 

83 

26 

64 

77 

28 

62 

72 

30 

60 

70 

35 

57 

63 

In  large  bottling  establishments  continuous  pasterizers  of  various 
designs  in  which  the  temperatue  is  automatically  regulated  are  used. 
In  most  of  these  the  bottles  are  heated  gradually  as  they  pass  through 
sprays  or  tanks  of  water  of  gradually  increasing  temperature  until 


Bulletin  359]  FRUIT  BEVERAGE  INVESTIGATIONS  561 

the  pasteurizing  temperature  is  reached.  After  pasteurization  the  bot- 
tles pass  through  water  of  progressively  decreasing  temperature. 
Figure  12  illustrates  a  pasteurizer  of  this  kind. 

A  homemade  continuous  pasteurizer  was  recently  observed  in 
operation.  It  consisted  of  a  wooden  tank  about  seventy-five  feet  long, 
about  three  feet  wide,  and  about  two  feet  deep.  It  was  divided  into 
several  sections  and  was  filled  with  water  heated  by  open  steam  coils. 
The  bottles  of  juice  were  placed  in  perforated  sheet  metal  boxes.  These 
were  carried  progressively  through  the  water  in  the  several  sections 
of  the  pasteurizer.  The  different  sections  were  maintained  at  different 
temperatures  so  that  the  bottles  were  subjected  to  gradually  increas- 
ing temperatures. 

A  very  satisfactory  automatic  pasteurizer  holding  seventy-two 
dozen  bottles  at  a  charge  can  be  bought  and  installed  for  $325.  A 
ten  horse  power  boiler  to  operate  it  can  be  obtained  for  about  $250. 
The  capacity  of  this  pasteurizer  is  about  five  thousand  bottles  in  eight 
hours. 

Keeping  Quality  of  Fruit  Beverages. — Carbonated  orange  and 
lemon  beverages  in  bottles  were  found  to  deteriorate  rapidly  in  quality 
after  six  to  eight  weeks'  storage  at  room  temperatures.  They  must 
therefore  be  consumed  within  two  months  after  bottling. 

Carbonated  bottled  fruit  punch  made  from  loganberry  or  red 
grape  syrup,  combined  with  orange  and  lemon  syrups,  retained  its 
flavor  and  color  very  satisfactorily  for  six  months.  It  seems  a  more 
desirable  beverage  than  either  the  orange  or  lemon  beverages  alone. 

"Muscat  blend"  bottled  and  carbonated  has  retained  its  color  and 
flavor  for  at  least  fifteen  months.  Apparently  it  is  as  stable  as  ordinary 
bottled  grape  juice.  This  blend  was  made  from  equal  volumes  of 
vacuum  concentrated  Muscat  and  red  wine  grape  syrups.  No  sugar 
was  used  in  its  preparation. 

A  strawberry  beverage  after  about  three  months'  storage  became 
brown  in  color,  but  one  of  strawberry  and  blackberry  has  retained 
both  color  and  flavor  very  well  for  the  six  months  that  it  has  been 
stored. 

Loganberry  and  raspberry  beverages  have  retained  their  color 
and  flavor  very  satisfactorily  for  six  months. 

Pomegranate  carbonated  beverages  deteriorated  in  flavor  and  color 
during  storage  when  highly  diluted,  but  beverages  containing  a  large 
percentage  of  the  juice  have  retained  their  quality  very  well. 

Samples  of  all  varieties  of  bottled  carbonated  beverages  prepared 
in  our  experiments  are  still  under  observation  to  determine  changes 
in  flavor  and  color  on  prolonged  storage. 


562  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION 

Use  of  Fruit  Syrups  by  Commercial  Bottlers. — A  well  known 
bottling  establishment  which  distributes  bottled  carbonated  beverages 
throughout  the  Pacific  Coast  states  is  now  producing  several  bottled 
carbonated  fruit  beverages  from  citrus  fruit,  loganberry,  and  pine- 
apple syrups.  An  Oakland  bottling  company  is  now  marketing  logan- 
berry and  pineapple  bottled  carbonated  beverages.  A  Salem,  Oregon 
fruit  juice  company  has  for  several  years  successfully  marketed  large 
quantities  of  a  bottled,  carbonated  loganberry  beverage.  In  addition 
there  are  many  'near  fruit'  carbonated  beverages  on  the  market  made 
of  some  fruit  juice,  sugar,  artificial  color  and  flavor. 

Samples  of  syrups  were  distributed  to  several  bottlers  in  the  San 
Francisco  Bay  district  for  experimental  bottling  purposes.  With 
one  exception  all  reports  on  the  use  of  the  syrups  were  favorable.  The 
cause  of  the  unfavorable  report  was  the  fermentation  of  the  syrup 
before  it  was  used,  as  a  result  of  a  leaky  syrup  container. 

Bottlers  have  expressed  themselves  in  favor  of  the  fruit  beverages 
but  have  hesitated  to  undertake  their  manufacture  because  the  exist- 
ing 'cut-throat'  methods  of  competition  make  the  higher  price  of 
fruit  syrups  and  the  necessity  of  pasteurizing  a  serious  handicap. 
If,  however,  the  beverages  could  be  sold  at  ten  cents  a  bottle,  retail, 
bottlers  have  stated  that  it  is  commercially  possible  to  produce  carbon- 
ated fruit  beverages  with  a  profit  to  all  concerned.  Our  experience 
proves  that  this  price  will  be  paid  readily  by  a  large  proportion  of 
those  who  use  carbonated  beverages.  The  writers  therefore  sincerely 
believe  that  the  production  of  real  fruit  carbonated  bottled  beverages 
is  commercially  feasible. 

SEMI-COMMERCIAL  PRODUCTION  AND  SALE 

During  the  past  fifteen  months  approximately  five  thousand  bottles 
of  carbonated  fruit  beverages  were  prepared  and  sold  by  the  Fruit 
Products  Laboratory.  Approximately  five  hundred  bottles  of  fruit 
syrups  have  been  sold  during  the  past  six  months. 

Our  distribution  has  been  made  through  a  Berkeley  grocery  store 
and  by  direct  sale  at  the  Fruit  Products  Laboratory,  for  the  past 
eight  months.  For  a  period  of  two  months  the  products  were  on  sale 
in  an  Oakland  market. 

Syrups. — As  an  experiment,  a  few  eight  ounce  bottles  each  of 
loganberry,  strawberry,  orange,  raspberry,  fruit  punch,  and  black- 
berry syrups  were  placed  on  sale  in  the  East  Bay  Market.  The  syrups 
were  those  used  regularly  in  the  preparation  of  the  bottled  carbonated 
beverages  and  were  pasteurized  at  175°  F.  for  thirty  minutes. 


Bulletin  359]  FRUIT  BEVERAGE  INVESTIGATIONS  563 

Approximately  one  hundred  twenty  bottles  were  sold  during  the 
six  days  on  which  the  syrups  were  on  sale.  Many  of  the  sales  repre- 
sented repeat  orders,  usually  cases  in  which  a  customer  purchased  one 
bottle  for  trial  and  later  returned  for  six  bottles  or  more.  Reports 
from  customers  were  in  all  cases  favorable.  The  syrups  were  used  in 
most  cases  for  homemade  punch  for  childrens'  parties,  etc.,  but  some 
of  the  syrups  were  used  with  apple  pectin  for  jelly,  with  gelatin  for 
gelatin  desserts,  and  in  frozen  desserts.  Loganberry,  orange,  and  fruit 
punch  were  the  most  popular  syrups.  Approximately  twice  as  much 
loganberry  as  any  other  single  syrup  was  sold.  Its  intensely  red  color, 
brilliantly  clear  appearance,  and  pronounced  flavor  made  it  popular. 

Sales  of  this  syrup  at  the  University  have  also  been  very  satis- 
factory. Much  less  'sales  effort'  has  been  expended  on  the  syrups 
than  on  the  beverages.  Because  of  the  numerous  repeat  orders  for 
the  syrups  the  writers  believe  that  their  manufacture  affords  a  very 
promising  field  for  commercial  development ;  one  at  least  as  attractive 
as  the  production  of  bottled  carbonated  fruit  beverages. 

Bottled  Beverages. — On  Picnic  Day,  April  22,  1922,  at  the  Univer- 
sity Farm  five  hundred  bottles  of  assorted  carbonated  beverages 
(orange  not  included)  were  placed  on  sale  by  the  students.  The  entire 
lot  was  sold  in  less  than  three  hours.  There  were  many  repeat  orders 
and  several  hundred  would-be  purchasers  could  not  be  served.  Com- 
ment in  all  cases  was  favorable.  Loganberry,  Muscat  grape  blend, 
raspberry,  and  fruit  punch  were  most  popular.  Blackberry  and  pome- 
granate beverages  lacked  flavor.  No  one  objected  to  the  price  of  ten 
cents  a  bottle.    On  April  28,  1923,  similar  results  were  obtained. 

The  beverages  have  been  on  sale  at  the  Faculty  Club  on  the  Uni- 
versity campus,  where  a  steady  demand  has  developed.  The  beverages 
are  used  chiefly  at  evening  meetings  of  various  organizations  at  the 
club  and  for  sale  during  the  day  at  the  club's  cigar  stand. 

A  steady  demand  for  the  beverages  for  family  use  has  developed 
at  Sill's  Grocery  in  Berkeley.  Purchases  are  frequently  made  in  lots 
of  one  dozen  bottles.  The  sale  at  this  store  was  started  with  a  one 
day 's  demonstration.  No  effort  has  been  made  to  artificially  stimulate 
the  demand  since  the  first  day's  sale.  Continuation  of  satisfactory 
sales  therefore  represents  a  real  demand  for  the  products.  Loganberry, 
orange,  and  raspberry  beverages  have  been  most  popular  at  this  store. 

In  spite  of  the  'cash  and  carry'  feature  of  the  sales  made  in  the 
Fruit  Products  Laboratory,  sales  to  the  campus  public  have  been 
satisfactory  and  many  repeat  orders  have  been  received. 

During  the  winter  months  the  demand  has  been  limited. 


564  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

Wider  distribution  of  the  beverages  through  groceries,  cigar  stands, 
soda  fountains,  and  markets  will  be  attempted  during  the  coming 
summer.  Attempts  will  also  be  made  to  encourage  the  bottling  of 
fruit  beverages  by  commercial  concerns. 

Carbonated  Beverages  in  Bulk. — At  the  request  of  one  of  the 
senior  students  in  Agriculture,  five  gallons  of  carbonated  fruit  punch 
was  prepared  for  a  fraternity  dance.  It  was  enthusiastically  received 
and  the  fame  of  the  punch  soon  spread  to  other  student  organizations. 
Frequent  sales  of  the  carbonated  punch  in  bulk  are  now  made  and  the 
demand  for  it  is  increasing. 

The  carbonated  punch  has  been  prepared  by  mixing  heavily  car- 
bonated water,  chilled  to  slightly  above  32°  F.  before  carbonating, 
with  a  blend  of  red  grape,  or  loganberry,-  orange,  and  lemon  syrups. 
The  punch  is  immediately  placed  in  cold  storage  after  carbonating  and 
delivered  cold  to  the  customer. 

The  punch  has  been  prepared  in  fifty  gallon  lots  in  barrels  for 
functions  of  the  College  of  Agriculture. 

The  writers  believe  that  carbonating  fruit  punches  will  greatly 
increase  their  popularity  and  suggest  this  new  method  to  soda  foun- 
tains for  trial. 

The  University  will  not  remain  in  the  business  of  semi-commercial 
production  of  fruit  sj^rups,  bottled  beverages,  and  carbonated  punch 
indefinitely,  but  merely  long  enough  to  induce  commercial  agencies  to 
give  the  new  products  a  fair  trial. 

COST  OF  PRODUCTION  OF  FRUIT  SYRUPS  AND  CARBONATED 

BEVERAGES 

The  cost  of  producing  various  carbonated  fruit  beverages  in  the 
Fruit  Products  Laboratory  is  summarized  in  tables  3  and  4.  The  fruit 
was  purchased  in  many  cases  in  the  wholesale  fruit  markets.  *Oranges 
and  lemons  were  furnished  without  cost  to  the  University  by  the 
Exchange  Orange  Products  Company  of  San  Dimas  and  the  Exchange 
Lemon  Products  Company  of  Corona.  Grapes  were  obtained  from  the 
Viticulture  Division  at  the  University  Farm,  Davis,  at  prices  prevail- 
ing at  the  time  of  harvest. 

*  The  writers  wish  to  express  their  appreciation  particularly  to  Messrs. 
Wilson,  Cassell,  May,  and  House,  of  these  companies,  for  fruit  furnished  for 
our  experiment  b. 


Bulletin  359] 


FRUIT   BEVERAGE   INVESTIGATIONS 


565 


Bottlers  usually  make  a  charge  to  the  customer  for  bottles  and 
cases.  In  some  instances  this  is  one  dollar  and  fifty  cents  per  case 
of  two  dozen  bottles,  or  at  the  rate  of  approximately  six  cents  per 
bottle.  This  charge  is  refunded  on  return  of  the  cases  and  bottles. 
In  table  4  the  last  column  represents  the  net  cost  to  the  bottler  who 
prepares  his  own  syrups. 

It  should  be  possible  to  sell  all  of  these  beverages  at  ten  cents  per 
bottle  retail,  provided  the  usual  deposit  for  bottles  and  cases  is 
charged. 

TABLE  3 
Cost  of  Fruit  Syrups 


Fruit 


Apple 

Blackberry 

Red  Grape 

Muscat  Grape 

Lemon 

Loganberry 

Orange 

Pomegranate.. 

Raspberry 

Strawberry 


Cost  of 
one  ton 


Syrup  Cost  of  One  Gallon 


$15.00 

143.00 

50.00 

50.00 

20.00 

143.00 

20.00 

20.00 

333.00 

205.00 


Fruit 


$    .50 

.56 
.90 
.63 
.40 
.70 
.10 
.14 
1.26 
.84 


Sugar 


0 
.34 
0 
0 
.36 
.30 
.36 
.12 
.34 
.36 


Power  and 
Labor 


.25 
.15 
.25 
.25 

.15 
15 
15 
20 
15 
15 


Pasteur- 
izing and 
Container 


.20 
.20 
.20 
.20 
.20 
.20 
.20 
.20 
.20 
.20 


Total 


$1.00 

1.25 

1.35 

1.08 

.81 

1.35 

.81 

.66 

1.95 

1.55 


TABLE  4 

Cost  of  Fruit  Beverages 


Kind 

Beverage  Cost  of  One  8-ounce  Bottle  in  Cents 

Syrup 

Labor 

Bottle 

Pasteur- 
izing 

Label 

Total  with 
Bottle 

Total 
Exclusive 
of  Bottle 

Apple 

Blackberry 

Red  Grape 

Muscat  Grape  .. 

Lemon 

Loganberry 

Orange 

Pomegranate  .... 

Raspberry 

Strawberry 

1.25c 
1.56 
1.69 
1.35 
1.01 
1.69 
1.01 
.83 
2.44 
1.94 

.46c 

.46 

.46 

.46 

.46 

.46 

.46 

.46 

.46 

.46 

2.5c 

2.5 

2.5 

2.5 

2.5 

2.5 

2.5 

2.5 

2.5 

2.5 

.5c 

.5 

.5 

.5 

.5 

.5 

.5 

.5 

.5 

.5 

lc 

4.81c 

5.12 

5.25 

4.91 

4.57 

5.25 

4.57 

4.39 

6.00 

5.40 

2.31c 

2.62 

2.75 

2.41 

2.07 

2.75 

2.07 

2.89 

3.50 

2.90 

&OKT 


1 

j 


w 
w 


TT- 

i  i 


> 


BOTTLE        U  ' 


..IT 

*<*  *± i_ 


// 


R/hSTTTlfTf/ZE 

or  sroRtr 

r 


u. 


A  DP     SyKVP 
TO  SCO/9  JV/fT/K 
0OTTL£$ 


rr 
■  iii 


/fPP 

rr 
j 


BOTTLES 


TT 

.11 


/^stev/wze 


BERRIES     /}/ip  CHERRIES 

kco  ex*»*3  fftpn£9  /tnt 

C/TKU3    rffUITS \  u/Hitf  r/r/>Pr% 

roue  ex* Af/t  res         L  WHI  T£  e*»PEa 


Fig.    15. — Outline    of    processes    of    preparing    carbonated    beverages    from 
various  fruits. 


Bulletin  359]  FRUIT  BEVERAGE  INVESTIGATIONS  567 


SUMMARY  AND  CONCLUSIONS 

1.  Most  of  the  so-called  fruit  beverages  now  on  the  market  contain 
little  or  no  fruit  juice. 

2.  Our  experiments  have  demonstrated  that  excellent  syrups  and 
carbonated  beverages  may  be  made  from  loganberries,  raspberries, 
oranges,  lemons,  and  apples,  and  from  blends  of  strawberries  with 
blackberries,  of  Muscat  with  red  wine  grapes,  of  raisins  with  oranges 
and  lemons,  and  of  loganberries,  red  grapes  or  pomegranates  with 
oranges  and  lemons. 

3.  Sugar  was  used  in  the  preparation  of  all  syrups  except  those 
made  from  grapes  and  apples. 

4.  Concentration  by  freezing  and  in  a  glass  lined  vacuum  pan  were 
both  satisfactory  methods  of  concentrating  grape,  apple,  and  citrus 
fruit  juices. 

5.  Syrups  were  preserved  satisfactorily  by  pasteurizing  in  glass  at 
175°  F.  for  thirty  minutes,  or  by  storage  at  0  to  15°  F.  in  sealed  con- 
tainers without  pasteurization.  Glass  containers  were  better  than 
enamel  lined  tin  containers  for  pasteurized  syrups. 

Preservatives  imparted  a  disagreeable  flavor  and  their  use  is  not 
recommended. 

6.  The  syrups  were  found  excellent  for  the  preparation  of  carbon- 
ated bottled  beverages,  for  soda  fountain  use,  the  preparation  of 
centers  for  candies  and  for  home  use  in  the  preparation  of  punch, 
gelatin  desserts,  sauces,  jellies,  etc. 

7.  By  the  use  of  a  small  carbonating  and  bottling  outfit,  approxi- 
mately five  thousand  bottles  of  carbonated  fruit  beverages  were  pre- 
pared and  sold.  Approximately  one  thousand  bottles  of  various  bever- 
ages were  prepared  experimentally  and  distributed  to  classes,  visitors, 
and  others  for  expression  of  opinion.  Comments  were  generally  favor- 
able.   A  retail  price  of  ten  cents  per  bottle  was  willingly  paid. 

8.  Loganberry,  grape,  strawberry-blackberry  blend,  apple,  rasp- 
berry, and  fruit  punch  bottled  carbonated  beverages  have  retained 
their  flavor  and  color  satisfactorily  for  from  six  to  fifteen  months. 
Orange,  lemon,  and  strawberry  deteriorated  markedly  in  quality  after 
two  months'  storage. 

9.  Pasteurizing  at  150°  F.  for  thirty  minutes  destroyed  yeasts  and 
prevented  spoiling  of  carbonated  fruit  beverages  heavily  inoculated 
with  yeast,  mold,  and  bacteria.  Heat  resistant  molds  and  bacteria 
were  not  killed  by  this  treatment,  but  the  carbon  dioxide  gas  pre- 
vented their  development. 


568  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

10.  Many  commercial  bottlers  possess  all  necessary  equipment  for 
preparing  carbonated  beverages  from  fruit  syrups.  Some  bottlers  do 
not  possess  pasteurizing  equipment,  but  this  equipment  can  be  built  or 
purchased  at  moderate  cost. 

11.  As  a  result  of  the  investigations  reported  in  this  bulletin  the 
writers  are  convinced  that  carbonated  fruit  beverages  can  be  made 
and  sold  at  retail  for  ten  cents  a  bottle  with  a  profit  to  all  concerned. 
Our  semi-commercial  manufacture  and  sales  have  demonstrated  that 
a  market  exists  for  them.  A  good  demand  for  the  syrups  for  home 
use  was  found.  The  writers  recommend  that  the  syrups  be  prepared 
in  centrally  located  factories  and  distributed  in  pasteurized  form  or 
under  refrigeration  to  bottlers,  soda  fountains,  and  grocers. 

12.  A  large  proportion  of  the  surplus  and  cull  fruits  of  California 
might  be  utilized  to  advantage  in  the  preparation  of  fruit  syrups  and 
carbonated  beverages. 

Recommended  processes  of  manufacture  are  shown  graphically  in 
figure  15. 


STATION  PUBLICATIONS  AVAILABLE  FOE  FEEE  DISTEIBUTION 


BULLETINS 

No.  No. 

253.  Irrigation   and   Soil  Conditions  in  the  328. 

Sierra  Nevada  Foothills,  California.  331. 

261.  Melaxuma    of    the    Walnut,    "Juglans  332. 

regia."  334. 

262.  Citrus   Diseases   of  Florida   and   Cuba 

Compared  with  those  of  California.  335. 

263.  Size  Grades  for  Ripe  Olives. 

268.  Growing  and  Grafting  Olive  Seedlings.  336. 

270.  A  Comparison  of  Annual  Cropping,  Bi- 
ennial Cropping,  and  Green  Manures  337. 
on  the  Yield  of  Wheat.  339. 

273.  Preliminary  Report  on  Kearney  Vine- 
yard Experimental  Drain.  340. 

275.  The  Cultivation  of  Belladonna  in  Cali- 

fornia. 341. 

276.  The   Pomegranate.  342. 

278.  Grain   Sorghums.  343. 

279.  Irrigation  of  Rice  in  California.  344. 

280.  Irrigation  of  Alfalfa  in  the  Sacramento 

Valley.  345. 

283.  The  Olive  Insects  of  California. 

285.  The  Milk  Goat  in  California.  346. 

286.  Commercial    Fertilizers.  347. 

287.  Vineear  from  Waste  Fruits. 

294.   Bean    Culture   in   California.  348. 

297.  The  Almond  in  California.  349. 

298.  Seedless  Raisin  Grapes. 

299.  The  Use  of  Lumber  on  California  Farms.  350. 
304.  A  study  on  the  Effects  of  Freezes  on  351. 

Citrus   in   California.  352. 
308.  I.  Fumigation  with  Liquid  Hydrocyanic 

Acid.  II.  Physical  and  Chemical  Prop-  353. 

erties  of  Liquid  Hydrocyanic  Acid.  354. 

312.  Mariout  Barley.  355. 

313.  Pruning  Young   Deciduous  Fruit  Trees.  356. 

316.  The  Kaki  or  Oriental  Persimmon. 

317.  Selections  of   Stocks  in  Citrus   Propa-  357. 

gation. 
319.  Caprifigs  and  Caprification. 
321.   Commercial  Production  of  Grape  Syrup.  358. 

324.  Storage  of  Perishable  Fruit  at  Freezing 

Temperatures.  359. 

325.  Rice  Irrigation  Measurements  and  Ex- 

periments    in      Sacramento     Valley, 
1914-1919. 


Prune  Growing  in  California. 

Phylloxera-Resistant  Stocks. 

Walnut  Culture  in  California. 

Preliminary  Volume  Tables  for  Second- 
Growth  Redwoods. 

Cocoanut  Meal  as  a  Feed  for  Dairy 
Cows  and  Other  Livestock. 

The  Preparation  of  Nicotine  Dust  as 
an  Insecticide. 

Some  Factors  of  Dehydrater  Efficiency. 

The  Relative  Cost  of  Making  Logs  from 
Small    and   Large   Timber. 

Control  of  the  Pocket  Gopher  in  Cali- 
fornia. 

Studies  on  Irrigation  of  Citrus  Groves. 

Hog  Feeding  Experiments. 

Cheese  Pests  and  Their  Control. 

Cold  Storage  as  an  Aid  to  the  Market- 
ing of  Plums. 

Fertilizer  Experiments  with  Citrus 
Trees. 

Almond    Pollination. 

The  Control  of  Red  Spiders  in  Decidu- 
ous  Orchards. 

Pruning  Young  Olive  Trees. 

A  Study  of  Sidedraft  and  Tractor 
Hitches. 

Agriculture  in  Cut-over  Redwood  Lands. 

California  State  Dairy  Cow  Competition. 

Further  Experiments  in  Plum  Pollina- 
tion. 

Bovine  Infectious  Abortion. 

Results  of  Rice  Experiments  in  1922. 

The  Peach  Twig  Borer. 

Observations  on  Some  Rice  Weeds  in 
California. 

A  Self-mixing  Dusting  Machine  for 
Applying  Dry  Insecticides  and 
Fungicides. 

Black  Measles,  Water  Berries,  and 
Related    Vine    Troubles. 

Fruit  Beverage  Investigations. 


CIRCULARS 

No.  No. 

70.  Observations    on    the    Status    of    Corn  166. 

Growing  in  California.  167. 

82.  The  Common  Ground  Squirrel  of  Cali-  169. 

fornia.  170. 
87.  Alfalfa. 

110.  Green  Manuring  in  California.  172. 

111.  The  Use  of  Lime  and  Gypsum  on  Cali-  173. 

fornia  Soils. 

113.  Correspondence  Courses  in  Agriculture.  174. 

117.  The    Selection    and    Cost    of    a    Small  175. 

Pumping  Plant. 

127.   House  Fumigation.  178. 

136.  Melilotua   indica    as    a    Green-Manure  179. 

Crop  for  California. 

144.   Oidium  or  Powdery  Mildew  of  the  Vine.  182. 
148.   "Lungworms." 

151.  Feeding  and  Management  of  Hogs.  183. 

152.  Some  Observations  on  the  Bulk  Hand-  184. 

ling  of  Grain  in  California.  188. 

155.  Bovine  Tuberculosis.  190. 

157.   Control  of  the  Pear  Scab.  193. 

159.  Agriculture  in  the  Imperial  Valley.  198. 

160.  Lettuce  Growing  in  California.  199. 

161.  Potatoes  in  California.  201. 
165.   Fundamentals   of   Sugar   Beet  Culture  202. 

under  California  Conditions. 


The  County  Farm  Bureau. 

Feeding  Stuffs  of  Minor  Importance. 

The   1918   Grain  Crop. 

Fertilizing  California  Soils  for  the  1918 

Crop. 
Wheat  Culture. 
The    Construction    of    the    Wood-Hoop 

Silo. 
Farm  Drainage  Methods. 
Progress  Report  on  the  Marketing  and 

Distribution  of  Milk. 
The  Packing  of  Apples  in  California. 
Factors    of    Importance    in    Producing 

Milk  of  Low  Bacterial  Count. 
Extending  the  Area  of  Irrigated  Wheat 

in  California  for  1918. 
Infectious  Abortion  in  Cows. 
A  Flock  of  Sheep  on  the  Farm. 
Lambing  Sheds. 

Agriculture  Clubs  in  California. 
A  Study  of  Farm  Labor  in  California. 
Syrup  from  Sweet  Sorghum. 
Onion  Growing  in  California. 
Helpful  Hints  to  Hog  Raisers. 
County   Organizations   for  Rural   Fire 

Control. 


CIRCULARS — Continued 


No.  No. 

203.  Peat  as  a  Manure  Substitute.  238. 

205.  Blackleg.  239. 

206.  Jack  Cheese. 

208.  Summary  of  the  Annual  Reports  of  the  240. 

Farm  Advisors  of  California. 

209.  The  Function  of  the  Farm  Bureau.  241. 

210.  Suggestions  to  the  Settler  in  California. 

212.   Salvaging  Rain-Damaged  Prunes.  242. 

214.  Seed  Treatment  for  the  Prevention  of  244. 

Cereal   Smuts.  245. 

215.  Feeding  Dairy  Cows  in  California.  246. 

217.  Methods   for   Marketing   Vegetables   in 

California.  247. 

218.  Advanced    Registry    Testing   of    Dairy  248. 

Cows. 

219.  The  Present  Status  of  Alkali.  249. 

224.  Control    of    the    Brown    Apricot    Scale  250. 

and  the  Italian  Pear  Scale  on  Decid- 
uous Fruit  Trees.  251. 

225.  Propagation  of  Vines. 

228.   Vineyard   Irrigation  in  Arid  Climates. 

230.  Testing  Milk,    Cream,    and    Skim   Milk  252. 

for  Butterfat.  253. 

232.  Harvesting    and    Handling    California  254. 

Cherries  for  Eastern  Shipment. 

233.  Artificial  Incubation.  255. 

234.  Winter  Injury  to  Young  Walnut  Trees 

during  1921-22.  256. 

235.  Soil  Analysis  and  Soil  and  Plant  Inter-  257. 

relations.  258. 

236.  The  Common  Hawks  and  Owls  of  Cali-  259. 

fornia    from     the     Standpoint   of  the 
Rancher. 

237.  Directions  for  the  Tanning  and  Dress- 

ing of  Furs. 


The  Apricot  in  California. 

Harvesting  and  Handling  Apricots  and 
Plums  for  Eastern  Shipment. 

Harvesting  and  Handling  Pears  for 
Eastern   Shipment. 

Harvesting  and  Handling  Peaches  for 
Eastern   Shipment. 

Poultry  Feeding. 

Central  Wire  Bracing  for  Fruit  Trees. 

Vine  Pruning  Systems. 

Desirable  Qualities  of  California  Bar- 
ley for  Export. 

Colonization  and  Rural  Development. 

Some  Common  Errors  in  Vine  Pruning 
and  Their  Remedies. 

Replacing  Missing  Vines. 

Measurement  of  Irrigation  Water  on 
the   Farm. 

Recommendations  Concerning  the  Com- 
mon Diseases  and  Parasites  of 
Poultry    in    California. 

Supports  for  Vines. 

Vineyard   Plans. 

The  Use  of  Artificial  Light  to  Increase 
Winter  Egg  Production. 

Leguminous  Plants  as  Organic  Fertil- 
izer in  California  Agriculture. 

The  Control  of  Wild  Morning  Glory. 

The  Small-Seeded  Horse  Bean. 

Thinning  Deciduous  Fruits. 

Pear  By-products. 


